A hollow single cylinder jack load box

Abstract

The present invention relates to a load box used in a self-balancing static load test of a foundation pile, and in particular to a load box that uses only one jack inside. A hollow single-cylinder jack load box comprises an upper plate, a lower plate and a hollow single-cylinder jack. The hollow single-cylinder jack comprises a liquid inlet pipe, a liquid outlet pipe, a cylinder body and a piston. A groove is provided on the cylinder body around its center, and the axial direction of the groove is consistent with the axial direction of the cylinder body; the piston and the groove are clearance-matched, and the bottom thereof forms a cavity with the bottom of the groove; the upper plate and the lower plate are respectively installed on the top and the bottom of the cylinder body, and move up and down together with the piston and the cylinder body. The present invention has the following advantages: 1. The nodes of the cylinder body are reduced, and the effectiveness of the push area of ​​the load box is improved. 2. The slurry quality is guaranteed and the filling rate is improved. 3. It is ensured that the engineering pile meets the design requirements of pull-out resistance. 4. The strength and integrity of the foundation pile body are guaranteed. 5. The bottom of the cavity formed by the bottom of the piston and the bottom of the groove is arc-shaped, so that the liquid can be drained as soon as possible.

Description

Technical Field

[0001] The invention relates to a load box used in a self-balancing static load test of a pile foundation, in particular to a load box with only one jack inside. Background Art

[0002] In the self-balancing static load test of pile foundation, the load box used generally has only one liquid injection tube, so that after the test, the space between the cylinder and the piston of the load box is filled with a non-solidifying liquid. As a result, after the self-balancing static load test of the pile foundation, the liquid in the load box cylinder is squeezed out and the pile is displaced under the vertical compression state of the project.

[0003] Although some load boxes can achieve drainage and grouting through two pipes, since the two pipes are at the same elevation on the upper side of the cylinder body, during grouting, only the liquid above the outlet elevation can be squeezed out, and the liquid below the outlet elevation cannot be completely drained, resulting in the injected slurry being diluted by the retained liquid, thereby reducing the concentration of the slurry, and the final setting strength of the slurry is seriously reduced, which cannot meet the reinforcement requirements. In addition, the general load box has multiple jacks, with many gaps between the jacks and many connection nodes, which can easily lead to leakage of liquid under high pressure and affect loading. Summary of the invention

[0004] The purpose of the present invention is to solve the problems existing in the prior art and to provide a hollow single-cylinder jack load box with fewer nodes, which can ensure the quality of slurry and improve the filling rate.

[0005] In order to achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a hollow single-cylinder jack load box, comprising an upper plate, a lower plate and a hollow single-cylinder jack, the hollow single-cylinder jack comprising a liquid inlet pipe, a liquid outlet pipe, a cylinder body and a piston, a groove is provided on the cylinder body around its center, and the axial direction of the groove is consistent with the axial direction of the cylinder body; the piston is fitted with the groove, and its bottom forms a cavity with the bottom of the groove, and through holes I and II are provided on opposite sides of the piston, which are consistent with the axial direction of the cylinder body, the top of through hole I is connected to the liquid inlet pipe passing through the upper plate, and the bottom is connected to the cavity, the top of through hole II is connected to the liquid outlet pipe passing through the upper plate, and the bottom is connected to the cavity, a pipe groove, an elastic member and a hollow long tube are designed in through hole II, one end of the elastic member is fixed to the top of the pipe groove, and the other end is connected and fixed to the hollow long tube, the bottom of the hollow long tube extends out of through hole II and is close to the bottom of the groove, and is connected to the cavity through a number of openings provided at its bottom; the upper plate and the lower plate are respectively installed at the top and bottom of the cylinder body, and move up and down together with the piston and the cylinder body.

[0006] Furthermore, it also includes an anti-pullout locking device, which is used to limit the piston in the cylinder body when it moves upward. It includes an anti-pullout locking head and an anti-pullout locking groove that match each other. The anti-pullout locking head is arranged at the upper position of the cylinder body, and its head end faces the outer wall of the piston; the anti-pullout locking groove is arranged at the lower position of the piston, and its open end faces the inner wall of the groove.

[0007] Preferably, the anti-pullout lock includes a lock head, a spring and a base connected in sequence, the lock head is restricted in the through hole by the piston, the base is fixed to the cylinder body, and the spring is compressed between the lock head and the base.

[0008] Preferably, there are at least two anti-pullout locking devices, which are arranged opposite to each other.

[0009] Preferably, a sealing groove is provided on the piston near the inner wall of the groove for accommodating a sealing ring, and the sealing groove is located below the anti-pullout locking groove.

[0010] Furthermore, it also includes a pressure-limited explosive grouting device, which is arranged in a groove on the top of the piston, including a vertical pipe for grouting outside the cylinder and a reversing pipe. There are two vertical pipes for grouting outside the cylinder, which are used for grouting outside the cylinder and a lower displacement wire protective sleeve. The lower displacement wire is fixed on the vertical pipe for grouting outside the cylinder, and the two ends of the reversing pipe are respectively inserted into the vertical pipe for grouting outside the cylinder.

[0011] Preferably, a grouting valve is installed in the reversing pipe, and the grouting valve includes a pressure relief channel, a solid pressure limiting plate and a hollow screw. The solid pressure limiting plate is arranged between the pressure relief channel and the hollow screw, and its pressure limiting value is less than the pressure bearing value of the reversing pipe.

[0012] Preferably, an inner grouting valve and an outer grouting valve are respectively provided on the inner wall and the outer wall of the groove; the pressure limiting value of the solid pressure limiting plate of the outer grouting valve is greater than the pressure limiting value of the solid pressure limiting plate of the inner grouting valve.

[0013] Preferably, the bottom shape of the cavity is arc-shaped.

[0014] Preferably, a sealing ring groove is provided around the circumference of the upper portion of the hollow long tube for accommodating the sealing ring.

[0015] Only one jack is used, which can reduce the multi-point connection of the cylinder body, improve the effectiveness of the load box pushing area, and detonate the grouting valve, the inner grouting valve, and the outer grouting valve through grouting, so as to reinforce the load box and the engineering pile to form a continuous whole, ensure the strength and integrity of the foundation pile body, and effectively transfer the upper load of the load box to the lower pile body of the load box.

[0016] Compared with the prior art, the present invention has the following advantages:

[0017] 1. Reduce the number of jacks and use only one jack, which reduces the nodes of the cylinder body and improves the effectiveness of the load box pushing area.

[0018] 2. The pipe groove, elastic parts and hollow long tube are designed in through hole II to ensure the cavity in the cylinder before grouting, so that the grouting body in the cylinder body is high-purity pure slurry, which ensures the slurry quality and improves the filling rate.

[0019] 3. The anti-pullout locking device ensures that the engineering piles meet the anti-pullout design requirements after the self-balancing static load test of the foundation piles.

[0020] 4. The setting of the pressure-limited explosive grouting device fills the hollow space of the cylinder body and other gaps, ensuring the strength and integrity of the foundation pile body, so that it can effectively transfer the upper load of the load box to the lower pile body of the load box.

[0021] 5. The bottom of the cavity formed by the bottom of the piston and the bottom of the groove (i.e. the bottom of the groove) is arc-shaped, so that the liquid can be discharged as quickly as possible. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of the present invention;

[0023] Figure 2 for Figure 1 Schematic diagram of the structure of a hollow single cylinder jack;

[0024] Figure 3 for Figure 1 Schematic diagram of the structure of the hollow long tube;

[0025] Figure 4 for Figure 1 Schematic diagram of the structure of the medium pull-out resistant lock;

[0026] Figure 5 for Figure 1 Schematic diagram of the structure of the middle grouting valve;

[0027] Figure 6 for Figure 1 Structural schematic diagram of medium-limited-pressure explosive grouting device;

[0028] Figure 7 for Figure 1 Schematic diagram of the starting and ending states of the hollow single cylinder jack;

[0029] Figure 8 It is a schematic diagram of grouting outside the cylinder of the present invention;

[0030] Figure 1 Among them, 1. Hollow single-cylinder jack; 2. Upper plate; 3. Lower plate; 4. Pressure-limited explosive grouting device;

[0031] Figure 2 5, liquid inlet pipe; 6, liquid outlet pipe; 7, cylinder body; 8, piston; 9, pipe groove; 10, spring; 11, sealing ring; 12, hollow long pipe; 13, anti-pullout lock head; 14, inner grouting valve; 15, outer grouting valve; 16, rib; 17, anti-pullout lock groove; 18, sealing groove and sealing ring; 19, groove;

[0032] Figure 3 In the middle, 20, sealing ring groove; 21, opening;

[0033] Figure 4 In the middle, 22, lock; 23, spring; 24, base;

[0034] Figure 5 Among them, 25, pressure relief channel; 26, solid pressure limiting plate; 27, hollow screw;

[0035] Figure 6 Among them, 28, lower displacement wire; 29, lower displacement wire sheath and external grouting vertical conduit; 30, reversing pipe; 31, grouting valve. DETAILED DESCRIPTION

[0036] It should be noted that in the following embodiments of the present invention, the directional words are described according to the drawings and do not constitute a limitation to the present invention.

[0037] The following is combined with Figure 1-8 The present invention is further described in detail: a hollow single cylinder jack load box, such as Figure 1 As shown, it is composed of a hollow single-cylinder jack 1, an upper plate 2, a lower plate 3 and a pressure-limited explosive grouting device 4; the hollow single-cylinder jack 1 is installed between the upper plate 2 and the lower plate 3, and the pressure-limited explosive grouting device 4 is installed in the hollow single-cylinder jack 1.

[0038] like Figure 2-3 As shown, the hollow single-cylinder jack 1 includes a liquid inlet pipe 5, a liquid outlet pipe 6, a cylinder body 7 and a piston 8. The cylinder body 7 is a hollow ring. A groove is provided around the center of the cylinder body 7, and the axial direction of the groove is consistent with the axial direction of the cylinder body 7; the piston 8 is inserted into the groove and fits with the groove gap, and its bottom forms a cavity with the bottom of the groove. A liquid inlet hole and a liquid outlet hole consistent with the axial direction of the cylinder body are provided on opposite sides of the piston. The top of the liquid inlet hole is connected to the liquid inlet pipe 5 passing through the upper plate 1, and the bottom is connected to the cavity. The top of the liquid outlet hole is connected to the liquid outlet pipe 6 passing through the upper plate 1, and the bottom is connected to the cavity. A pipe groove 9, a spring 10 and a hollow long tube 12 are designed in the liquid outlet hole. The axial direction of the pipe groove 9 is consistent with the axial direction of the liquid outlet hole, and one end of the pipe groove 9 is located at the liquid outlet hole. The top of the spring 10 is connected and fixed thereto, and the bottom is connected and fixed to the top of the hollow long tube 12. The spring is compressed in the tube groove 9 by the hollow long tube 12; the bottom of the hollow long tube 12 extends out from the bottom of the liquid outlet and is close to the bottom of the groove, and is connected to the cavity through a plurality of openings 21 opened at its bottom. When a pressurized air pump is used to supply air from the liquid inlet pipe 5 for pressurization, the air pressure will press the liquid in the cylinder body 7 from the opening of the hollow long tube 12 to the hollow long tube and be discharged through the hollow long tube, ensuring the cavity in the cylinder body 7 before grouting, so as to achieve high-purity pure slurry in the cylinder afterwards; the upper plate and the lower plate are respectively installed at the top and the bottom of the cylinder body 7, and move up and down together with the piston 8 and the cylinder body 7.

[0039] In order to ensure that the piston 8 is limited within the cylinder 7 when it is active, and at the same time, when the upper end steel cage is subjected to upward pulling force, the load box can effectively transmit the pulling force to the lower steel cage, thereby ensuring that the engineering pile meets the pull-out design requirements after the self-balancing static load test of the foundation pile, an anti-pulling lock device is added between the piston and the cylinder, such as Figure 2 , Figure 4 As shown, the anti-pullout lock device includes an anti-pullout lock head 13 and an anti-pullout lock groove 17 that match each other. The anti-pullout lock head 13 is set at the upper position of the cylinder body, and includes a lock head 22, a spring 23 and a base 24 connected in sequence. The head end of the lock head 22 is arc-shaped and faces the outer wall of the piston 8. The spring 23 is compressed between the lock head 22 and the base 24. The base is fixed to the cylinder body 7. The anti-pullout lock groove 17 is set at the lower position of the piston, and its open end faces the inner wall of the groove. When the piston 8 moves upward to the position of the anti-pullout lock head 13 and the anti-pullout lock groove 17, the lock head 22 is ejected into the anti-pullout lock groove 17 under the action of the spring 23, thereby locking the piston and the cylinder body so that they no longer move relative to each other. In order to achieve better anti-pullout effect, two anti-pullout lock devices are designed and arranged relatively in the two side walls of the groove; of course, the anti-pullout lock structure is not limited to two, it can be multiple, and is generally designed according to the anti-pullout requirements (assuming that the anti-pullout capacity of each anti-pullout lock is a, and the overall anti-pullout requirement is b, then the number n≥b / a).

[0040] like Figure 2 As shown, since there is a gap between the piston 8 and the groove, in order to prevent water or slurry from leaking from the gap during the loading process, sealing grooves and sealing rings 18 are provided on opposite sides of the piston to ensure the sealing effect. The sealing grooves and sealing rings 18 are located below the anti-pullout lock groove 17.

[0041] like Figure 2 As shown, in order to ensure that the water can be drained as quickly as possible and with better drainage effect, the bottom surface of the groove is arc-shaped, and the bottom of the hollow long tube 12 is just in close contact with the lowest position of the arc. Figure 3 As shown, a sealing ring groove 20 is provided around the center of the hollow long tube 12 near the top thereof, for installing the sealing ring 11 to achieve sealing between the hollow long tube 12 and the liquid outlet tube 6 .

[0042] like Figure 7 As shown, water is injected into the cavity through the liquid inlet pipe 5. As the amount of water increases, the piston 8 moves upward relative to the cylinder body 7, and the spring 10 presses the hollow long tube 12 so that its bottom is always in close contact with the bottom of the groove. When the anti-pullout lock groove 17 moves to be opposite to the anti-pullout lock head 13, the anti-pullout lock head 13 pops out to lock the piston 8 and the cylinder body 7 so that they no longer move relative to each other.

[0043] Since the cylinder body 7 is a hollow structure and there are many gaps between the upper plate, the lower plate and the cylinder body, in order to make the reinforced load box and the engineering pile form a continuous whole, ensure the strength and integrity of the foundation pile body, and effectively transfer the load on the upper part of the load box to the pile body below the load box, a pressure-limited explosive grouting device is added, such as Figure 5-6 As shown, the pressure-limited explosive grouting device includes a lower displacement wire 28, a lower displacement wire sheath and external grouting vertical conduit 29, a reversing pipe 30 and a grouting valve 31. The lower displacement wire 28 is fixed in the lower displacement wire sheath and external grouting vertical conduit 29; there are two lower displacement wire sheath and external grouting vertical conduits 29, which are respectively installed at both ends of the reversing pipe 30, and the cylinder external grouting vertical pipe and the sheath pipe of the lower displacement wire are integrated into a multifunctional pipe, which can prevent the lower displacement wire 28 from being gripped by concrete and can also be used as a vertical conduit for grouting outside the cylinder; the lower displacement wire 28 is inserted into the lower displacement wire sheath at both ends of the reversing pipe 30. The horizontal part of the sheath and external grouting vertical conduit 29 is fixed to the groove 19 opened on the piston 8, so as to play a role in diversion; at the same time, the free ends of the lower displacement wire sheath and external grouting vertical conduit 29 and the reversing pipe 30 are extended out of the upper plate 1, and the vertical part length L of the reversing pipe 30 should be greater than the displacement value of the piston 8 when the self-balancing static load pile test is terminated; the grouting valve 31 is installed in the reversing pipe 30, which includes a pressure relief channel 25, a solid pressure limiting plate 26 and a hollow screw 27. The solid pressure limiting plate 26 is arranged between the pressure relief channel 25 and the hollow screw 27, and its pressure limiting value P a Less than the pressure bearing capacity P of the reversing tube 30 b When the loading pressure value is P a , P b When the slurry breaks through the solid pressure limiting plate 26, the pressure is released by the hollow screw 27, and the slurry fills the groove 19. Figure 8 The first detonation point A in the cylinder. In order to fill the hollow and each gap of the cylinder 7 with slurry, as Figure 2 , Figure 8 As shown, grouting valves are respectively provided on the inner wall and the outer wall of the piston groove 19, namely: the inner grouting valve 14 and the outer grouting valve 15. The inner grouting valve 14 and the outer grouting valve 15 have the same structure as the grouting valve 31. The pressure limiting value of the solid pressure limiting plate 26 of the inner grouting valve 14 is P 内 The pressure limit value of the solid pressure limit plate 26 of the outer grouting valve 15 is P 外 , P 内＜ P 外 , due to the solid pressure limiting plate pressure limiting value P of the inner grouting valve 14 内 Less than the pressure limit value P of the solid pressure limit plate 26 of the outer grouting valve 15 外 Therefore, the inner grouting valve 14 is detonated first, forcing the slurry to flow naturally to and fill the middle hollow of the jack, i.e. Figure 8The second detonation point B in the jack. When the middle hollow of the jack is filled, continue grouting until the outer grouting valve 15 is detonated, forcing the slurry to flow naturally to and fill the gap at the load box, that is, Figure 8 The third tipping point C in the.

[0044] In order to reinforce the groove 19, a rib 16 is provided on the groove. There are two ribs 16, which are evenly arranged around the circumference of the groove.

[0045] Implementation steps:

[0046] (i) Liquid injection and pressurization: When liquid injection and pressurization is performed, the liquid outlet pipe 6 is closed and liquid is injected from the liquid inlet pipe 5;

[0047] 1. When there is no pressure, the piston is in the initial position, the spring is under pressure, and the pressure value is P1=P2=P3=P4. Figure 7 (a) as shown;

[0048] 2. Start pressurizing, close the liquid outlet pipe 6, and pressurize from the liquid adding pipe 5; the spring always supports the hollow long tube to make it close to the bottom plate, and the pressure value is P1>P2>P3>P4;

[0049] 3. Continue to inject liquid and pressurize. When the anti-pullout lock groove 17 on the piston 8 reaches the position of the anti-pullout lock head 13, the anti-pullout lock head 13 pops out, locking the piston and making it unable to move. When the termination condition is reached, the pressure value P1=P2=P3=P4, such as Figure 7 (b) as shown;

[0050] (ii) Inflation and drainage: After the liquid injection is completed, inflation and drainage begin. During inflation and drainage, the liquid inlet pipe 5 and the liquid outlet pipe 6 are not closed;

[0051] 4. Start to inflate and discharge liquid: Inject gas from the liquid inlet pipe 5, the gas fills into the cylinder 7 from top to bottom, squeezes the liquid and discharges it from the liquid outlet pipe 6, the pressure value is P1>P2>P3>P4;

[0052] 5. Continue to inflate until the liquid outlet pipe 6 stops discharging liquid, indicating that the liquid in the cylinder has been exhausted. Stop inflating. After stopping, the pressure value is P1=P2=P3=P4;

[0053] (iii) Grouting: When the liquid outlet pipe 6 stops discharging liquid, grouting begins;

[0054] 6. Start grouting: inject from the liquid inlet pipe 5, the pressure value is P1>P2>P3>P4;

[0055] 7. Continue grouting until slurry overflows from the outlet pipe and then stops. After stopping, the pressure value is P1=P2=P3=P4;

[0056] (IV) Grouting into the pressure-limited explosive grouting device

[0057] 8. After closing the lower displacement wire sheath and external grouting vertical conduit at one end, continue grouting until grout overflows from the other side of the pipe and take samples;

[0058] 9. After sampling, the overflow end is closed, and the slurry is then injected at high pressure from the inlet end until the grouting valve 31 is detonated, forcing the slurry to flow naturally to and fill the groove 19 of the piston;

[0059] 10. Since the solid pressure limiting plate of the inner grouting valve has a pressure limiting value of P 内 The pressure limit value of the solid pressure limit plate 26 smaller than the outer grouting valve is P 外 , so the inner grouting valve is detonated first, forcing the slurry to flow naturally to and fill the middle hollow of the jack;

[0060] 11. When the middle hollow of the jack is filled, continue grouting until the outer grouting valve is detonated, forcing the slurry to flow naturally to and fill the gap at the load box.

[0061] In this embodiment, water is used as the loading liquid, which has better affinity with the slurry and lower cost than oil.

[0062] The above embodiment is only a preferred embodiment of the present invention and does not constitute a limitation of the present invention. The anti-pullout locking device can exist in any load box structure using the jack principle. The pressure-limited explosive grouting device and the anti-pullout locking device can exist in the same embodiment at the same time, or they can exist separately in different embodiments. That is, the pressure-limited explosive grouting device is suitable for any load box structure. In other words, in the above embodiment, the anti-pullout locking device, the pressure-limited explosive grouting device and the hollow single-cylinder jack can be matched in various ways to achieve different purposes and different technical effects. Any extension, deformation, etc. made by ordinary technicians in this field without departing from the working principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A hollow single cylinder jack load box, comprising an upper plate, a lower plate and a hollow single cylinder jack, characterized in that: The hollow single-cylinder jack includes a liquid inlet pipe, a liquid outlet pipe, a cylinder body, a piston, an anti-pullout locking device and a pressure-limited explosive grouting device. A groove is provided around the center of the cylinder body, and the axial direction of the groove is consistent with the axial direction of the cylinder body; the piston and the groove are matched with each other in a clearance, and its bottom forms a cavity with the bottom of the groove. Through holes I and II are provided on opposite sides of the piston. The top of through hole I is connected to the liquid inlet pipe passing through the upper plate, and the bottom is connected to the cavity. The top of through hole II is connected to the liquid outlet pipe passing through the upper plate, and the bottom is connected to the cavity. A pipe groove, an elastic member and a hollow long tube are designed in through hole II. One end of the elastic member is fixed to the top of the pipe groove, and the other end is connected and fixed to the hollow long tube. The bottom of the hollow long tube extends out of through hole II and is close to the bottom of the groove, and is connected to the cavity through a number of openings provided at the bottom; the upper plate and the lower plate are respectively installed at the top and the bottom of the cylinder body, and move up and down together with the piston and the cylinder body; The anti-pullout lock device is used to limit the piston in the cylinder body when it moves upward, and includes an anti-pullout lock head and an anti-pullout lock groove that match each other. The anti-pullout lock head is arranged at the upper position of the cylinder body, and its head end faces the outer wall of the piston. It includes a lock head, a spring and a base that are connected in sequence. The lock head is limited in the through hole by the piston, and the base is fixed to the cylinder body. The spring is compressed between the lock head and the base; the anti-pullout lock groove is arranged at the lower position of the piston, and its open end faces the inner wall of the groove; The pressure-limited explosive grouting device is arranged in the groove on the top of the piston, including a vertical pipe for grouting outside the cylinder and a reversing pipe. There are two vertical pipes for grouting outside the cylinder, which are used for grouting outside the cylinder and a protective sleeve for the lower displacement wire. The lower displacement wire is fixed on the vertical pipe for grouting outside the cylinder, and the two ends of the reversing pipe are respectively inserted into the vertical pipes for grouting outside the cylinder.

2. The hollow single cylinder jack load box according to claim 1, characterized in that: There are at least two anti-pullout locking devices, which are arranged opposite to each other.

3. The hollow single cylinder jack load box according to claim 2, characterized in that: A sealing groove is provided on the piston near the inner wall of the groove for accommodating a sealing ring, and the sealing groove is located below the anti-pullout locking groove.

4. The hollow single cylinder jack load box according to claim 1, characterized in that: A grouting valve is installed in the reversing pipe. The grouting valve includes a pressure relief channel, a solid pressure limiting plate and a hollow screw. The solid pressure limiting plate is arranged between the pressure relief channel and the hollow screw, and its pressure limiting value is less than the pressure bearing value of the reversing pipe.

5. The hollow single cylinder jack load box according to claim 4, characterized in that: An inner grouting valve and an outer grouting valve are respectively arranged on the inner wall and the outer wall of the groove; the pressure limiting value of the solid pressure limiting plate of the outer grouting valve is greater than the pressure limiting value of the solid pressure limiting plate of the inner grouting valve.

6. The hollow single cylinder jack load box according to claim 1, characterized in that: The bottom shape of the cavity is arc-shaped.

7. The hollow single cylinder jack load box according to claim 1, characterized in that: A sealing ring groove is provided on the upper part of the hollow long tube around its circumference for accommodating the sealing ring.

Images