Pile foundation active underpinning and jacking device, method and system

Abstract

The invention relates to the technical field of active underpinning, in particular to a pile foundation active underpinning jacking device, method and system.The pile foundation active underpinning jacking device comprises a bottom plate, a pile top fixedly connected to an underpinning pile, a plurality of stand columns vertically and fixedly arranged on the bottom plate, a middle seat plate horizontally and fixedly connected to the top ends of the stand columns, and a plurality of jacking devices, the middle seat plate is arranged on the base plate and forms a frame type structure with the stand column and the base plate, a center through hole is formed in the center position of the middle seat plate, the top plate is arranged on the upper portion of the middle seat plate and connected with the bottom of an original structure in an anchoring mode, the jacking driving assembly is arranged on the base plate, penetrates through the center through hole of the middle seat plate and is used for jacking the top plate, and the locking units are used for locking the middle seat plate. And the locking units are distributed in the circumferential direction of the jacking driving assembly and movably installed on the middle base plate, the force application ends of the locking units penetrate through the middle base plate and extend towards the top plate, the jack can be pulled out while the underpinning stability is ensured, the jack can be recycled, and the economic benefits are effectively improved.

Description

Technical Field

[0001] This invention relates to the field of active underpinning technology, specifically to an active underpinning and jacking device, method, and system for pile foundations. Background Technology

[0002] In recent years, urban traffic has become increasingly complex, and underground rail transit has developed rapidly, leading to a growing need for bridge pile foundation replacement construction. Since all processes of bridge pile foundation replacement are carried out under the bridge, the working conditions are limited. The use of an active replacement system can eliminate some of the deformation of the new piles and the replacement system, keeping the deformation of the piles and structures after replacement within a very small range. During replacement, high-strength, durable, and simple support components are used in conjunction with jacks, which can effectively improve construction efficiency and personnel safety.

[0003] Existing bridge pile replacement technologies are mainly divided into two categories based on the replacement method: passive replacement and active replacement. Passive replacement technology refers to the passive transfer of the original bridge pile load to the newly built replacement pile as the replacement structure deforms. During construction, the deformation and load of the bridge pile structure cannot be controlled or adjusted, resulting in relatively large deformations. Therefore, passive replacement is rarely used in actual construction. Active replacement technology refers to the dynamic control of the deformation and load of the replacement system, ensuring that the deformation of the replaced bridge pile can be completely controlled during construction. The replacement structure of active replacement technology is mainly pile-beam replacement. The principle is to transfer the existing bridge load to the replacement pile through the bridge pile and the newly built replacement beam structure, and then carry out the tunnel construction under the bridge. Therefore, the replacement pile needs to bear all the original bridge loads. At the same time, in the above process, the active replacement system uses jacks to support the original structure and then grouts to solidify. This results in a long active replacement time and the jacks cannot be removed after use, leading to a significant waste of money. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies by providing a pile foundation active underpinning and jacking device, method, and system to achieve the goal of quickly completing active underpinning.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] In a first aspect, the present invention provides a pile foundation active underpinning and jacking device, which is disposed between the underpinning pile and the original structure, comprising:

[0007] The base plate is fixedly connected to the top of the supporting pile;

[0008] The column has multiple columns, and the multiple columns are vertically fixed to the base plate;

[0009] The middle base plate is horizontally fixed to the top of the multiple columns and forms a frame structure with the columns and the base plate. A central through hole is provided at the center of the middle base plate.

[0010] The top plate is located on the upper part of the middle seat plate and is anchored to the bottom of the original structure;

[0011] A lifting drive assembly is disposed on the base plate and passes through the central through hole of the middle seat plate, for lifting the top plate;

[0012] Multiple locking units are distributed circumferentially along the lifting drive assembly and movably mounted on the middle base plate, with the force-applying ends of the multiple locking units extending through the middle base plate toward the top plate.

[0013] In some embodiments, the lifting drive assembly includes a jack, the bottom of which is disposed on the base plate, and its output end passes through the central through hole of the middle seat plate and abuts against the top plate.

[0014] In some embodiments, the locking unit is a locking bolt, the axis of which is perpendicular to the lower surface of the top plate.

[0015] In some embodiments, the number of locking bolts is 8 to 20, and a pressure gap is reserved between the top end of the locking bolt and the lower surface of the top plate.

[0016] Secondly, the present invention also provides a method for active pile foundation replacement, employing the jacking device described in any of the above claims, comprising the following steps:

[0017] S1. The jack applies a lifting force to the top plate until the preset load of the jack is reached;

[0018] S2. Maintain the preset load of the jack, and alternately tighten each locking unit according to the preset sequence of symmetrical grouping, so that the pre-tightening force generated by the locking unit is transmitted to the top plate.

[0019] S3. Apply torque to the locking unit in stages until the actual load on the jack is zero;

[0020] S4. Remove the jack.

[0021] In some embodiments, the symmetrical grouping order is as follows: among a plurality of locking bolts, two locking bolts of the same diameter that pass through the axis of the jack are symmetrical, and a plurality of locking bolts arranged in a counterclockwise direction between them form a group, wherein there are multiple symmetrical groups.

[0022] In some embodiments, the locking unit is tightened by five increments of torque, wherein the first torque is a manual pre-tightening and the last torque is 200-250 N·m.

[0023] Thirdly, the present invention also provides a pile foundation underpinning system, comprising:

[0024] At least two support piles, each of which is equipped with a corresponding lifting device;

[0025] The base plate of the lifting device is fixed to the top of the corresponding replacement pile, and the top plate is anchored to the bottom of the original structure.

[0026] In some embodiments, the preset load of each jacking device is set differently according to the bearing capacity of the corresponding replacement pile.

[0027] In some embodiments, the tightening of the locking bolts of adjacent lifting devices is performed asynchronously.

[0028] Furthermore, the beneficial effects of this application are as follows:

[0029] In the entire active pile foundation replacement operation, once the load applied by the jack to the top plate meets the requirements, the operator can manually tighten multiple locking bolts to replace the jacking force of the jack with the mechanical preload generated by the locking bolts. Furthermore, the multi-stage tightening process of the multiple locking bolts can reduce the actual load on the jack to zero. This ensures the stability of the replacement while allowing the jack to be removed and reused, effectively improving economic efficiency.

[0030] In addition, the entire process of the mechanical preload generated by the locking bolt permanently replacing the load held by the jack is all done manually by turning it with tools. During construction, the clear space for workers is 800mm, and the overall operating space is suitable, which further improves the efficiency of workers. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the overall structure of the active pile foundation replacement and jacking device provided by the present invention;

[0032] Figure 2 This is a top view of a portion of the structure of the active pile foundation underpinning and jacking device provided by the present invention;

[0033] Figure 3 This is a bottom view of a portion of the structure of the active pile foundation underpinning and jacking device provided by the present invention;

[0034] Figure 4 This is a schematic diagram of the structure of the replacement pile in the pile foundation replacement system provided by the present invention.

[0035] In the diagram: 1-Locking bolt, 11-Locking bolt No. 1, 12-Locking bolt No. 2, 13-Locking bolt No. 3, 14-Locking bolt No. 4, 15-Locking bolt No. 5, 16-Locking bolt No. 6, 17-Locking bolt No. 7, 18-Locking bolt No. 8, 19-Locking bolt No. 9, 110-Locking bolt No. 10, 111-Locking bolt No. 11, 112-Locking bolt No. 12, 113-Locking bolt No. 13, 114-Locking bolt No. 14, 115-Locking bolt No. 15, 116-Locking bolt No. 16, 2-Base plate, 3-Column, 4-Jack, 5-Middle base plate, 51-Central through hole, 6-Top plate, 7-Replacement pile. Detailed Implementation

[0036] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. In the description of the embodiments of this application, unless otherwise stated, " / " means "or", for example, A / B can mean A or B; "and / or" in the text is merely a description of the relationship between related objects, indicating that there can be three relationships, for example, A and / or B can mean: A alone, A and B at the same time, and B alone. In addition, in the description of the embodiments of this application, "multiple" means two or more. Hereinafter, the terms "first" and "second" are used for descriptive purposes only and should not be construed as implying or suggesting relative importance or implicitly indicating the number of indicated technical features. Thus, features defined with "first" and "second" can explicitly or implicitly include one or more of that feature. In the description of the embodiments of this application, unless otherwise stated, "multiple" means two or more.

[0037] like Figures 1-4 As shown, in a first aspect, the present invention provides a pile foundation active underpinning and jacking device, which is disposed between the underpinning pile 7 and the original structure, comprising:

[0038] The base plate 2 is fixedly connected to the top of the supporting pile 7;

[0039] The column 3 is multiple, and the multiple columns 3 are vertically fixed on the base plate 2;

[0040] The middle base plate 5 is horizontally fixed to the top of multiple columns 3 and forms a frame structure with the columns 3 and the base plate 2. A central through hole 51 is provided at the center of the middle base plate 5.

[0041] Top plate 6 is set on the upper part of the middle base plate 5 and is anchored to the bottom of the original structure;

[0042] A lifting drive assembly is installed on the base plate 2 and passes through the central through hole 51 of the middle seat plate 5, and is used to lift the top plate 6;

[0043] Multiple locking units are circumferentially distributed along the lifting drive assembly and movably mounted on the middle base plate 5. The force-applying ends of the multiple locking units extend through the middle base plate 5 toward the top plate 6. The lifting drive assembly includes a jack 4, the bottom of which is located on the base plate 2, and its output end extends through the central through hole 51 of the middle base plate 5 and abuts against the top plate 6. In the above structure,

[0044] The concrete surface at the top of the replacement pile 7 is leveled, and a rectangular base plate 2 is welded and installed. Multiple columns 3 are welded to the edge of the base plate 2. Preferably, four steel columns 3 are welded vertically to the four corners of the base plate 2. A central base plate 5 is welded to the top of the columns 3. The base plate 2, columns 3, and central base plate 5 form a closed steel frame. At the same time, a through hole 51 is opened in the center of the central base plate 5, and multiple bolt mounting holes are evenly distributed around its circumference. The top plate 6 is anchored to the bottom surface of the original structural beam and pier column by chemical anchors. The jack 4 is placed in the center of the base plate 2, and its piston rod passes through the through hole 51 in the center of the central base plate 5 and is in close contact with the bottom surface of the top plate 6.

[0045] In one possible implementation, the locking unit is a locking bolt 1, the axis of which is perpendicular to the lower surface of the top plate 6. The number of locking bolts 1 is 8 to 20, and a pressure gap is reserved between the top of the bolt of the locking bolt 1 and the lower surface of the top plate 6. Based on this, the present invention preferably has 16 locking bolts 1, but the specific number of locking bolts 1 can be increased or decreased according to actual needs. This application does not make a specific limitation on this. At the same time, the tool used by the user to tighten the locking bolts 1 is not specifically limited in the present invention. For ease of description, the tool used by the user is a pneumatic wrench.

[0046] In this embodiment, during the entire active pile foundation replacement operation, once the load applied by the jack 4 to the top plate 6 meets the requirements, manual operation can be performed by tightening multiple locking bolts 1 to replace the jacking force of the jack 4 with the mechanical preload generated by the locking bolts 1. Compared with the traditional jack 4, the structure is safer. Traditional hydraulic jack 4 often experiences pressure relief and stroke problems during use. The structure of this invention is simpler and has a lower failure rate. Moreover, the multiple locking bolts 1 are tightened in stages, which can make the actual load of the jack 4 zero. Thus, while ensuring the stability of the replacement, the jack 4 can be pulled out, making the jack 4 reusable and effectively improving economic efficiency.

[0047] Secondly, the present invention also provides a method for active pile foundation replacement, employing any of the above-mentioned jacking devices, comprising the following steps:

[0048] S1. Jack 4 applies a lifting force to the top plate 6 until the preset load of jack 4 is reached;

[0049] S2. Maintain the preset load of jack 4, and alternately tighten each locking unit according to the preset sequence of symmetrical grouping, so that the pre-tightening force generated by the locking unit is transmitted to the top plate 6.

[0050] S3. Apply torque to the locking unit in stages until the actual load on jack 4 is zero;

[0051] S4. Remove the jack 4.

[0052] For details, please refer to [link / reference]. Figure 3 The arrangement of the locking bolts 1 in the diagram is as follows: north is at the top and south at the bottom. The locking bolt 11 is located in the due north direction (0° azimuth). Then, the locking bolts 1 arranged counterclockwise from locking bolt 11 are locking bolts 2, 3, 4, 5, ..., 16. The angle between locking bolts 11 and 2 on the arc is 22.5°, the angle between locking bolts 2 and 3 on the arc is 22.5°, and so on. That is, the central angle formed by every two adjacent locking bolts 1 in the 16 locking bolts 1 is the same.

[0053] In one possible implementation, the symmetrical grouping order is as follows: among multiple locking bolts 1, two locking bolts 1 of the same diameter that pass through the axis of the jack 4 are symmetrical, and multiple locking bolts 1 arranged in a counterclockwise direction between them form a group, wherein there are multiple symmetrical groups.

[0054] But only for Figure 3 For example, in the above embodiment, the symmetrical grouping of multiple locking bolts 1 is as follows: No. 1 locking bolt 11 to No. 9 locking bolt 19, including: No. 1 locking bolt 11, No. 2 locking bolt 12, No. 3 locking bolt 13, No. 4 locking bolt 14, No. 5 locking bolt 15, No. 6 locking bolt 16, No. 7 locking bolt 17, No. 8 locking bolt 18, and No. 9 locking bolt 19;

[0055] Locking bolts 15 to 13, including: No. 5 locking bolt 15, No. 6 locking bolt 16, No. 7 locking bolt 17, No. 8 locking bolt 18, No. 9 locking bolt 19, No. 10 locking bolt 110, No. 11 locking bolt 111, No. 12 locking bolt 112, and No. 13 locking bolt 113;

[0056] Locking bolts 13 to 111, including: locking bolt 13, 14, 15, 16, 17, 17, 18, 18, 19, 110, and 111;

[0057] Locking bolts 17 to 15, including: No. 7 locking bolt 17, No. 8 locking bolt 18, No. 9 locking bolt 19, No. 10 locking bolt 110, No. 11 locking bolt 111, No. 12 locking bolt 112, No. 13 locking bolt 113, No. 14 locking bolt 114, and No. 15 locking bolt 115;

[0058] Locking bolts 12 to 10, including: No. 2 locking bolt 12, No. 3 locking bolt 13, No. 4 locking bolt 14, No. 5 locking bolt 15, No. 6 locking bolt 16, No. 7 locking bolt 17, No. 8 locking bolt 18, No. 9 locking bolt 19, and No. 10 locking bolt 110;

[0059] Locking bolts 18 to 16, including: No. 8 locking bolt 18, No. 9 locking bolt 19, No. 10 locking bolt 110, No. 11 locking bolt 111, No. 12 locking bolt 112, No. 13 locking bolt 113, No. 14 locking bolt 114, No. 15 locking bolt 115, and No. 16 locking bolt 116;

[0060] Locking bolts 14 to 12, including: No. 4 locking bolt 14, No. 5 locking bolt 15, No. 6 locking bolt 16, No. 7 locking bolt 17, No. 8 locking bolt 18, No. 9 locking bolt 19, No. 10 locking bolt 110, No. 11 locking bolt 111, and No. 12 locking bolt 112;

[0061] Locking bolts 16 to 14, numbered 114, include: locking bolts 16, 17, 18, 19, 110, 111, 112, 113, and 114, totaling eight groups.

[0062] The preset sequence is as follows: First, manually tighten the No. 1 locking bolt (11 to 9, 19), then tighten the No. 5 locking bolt (15 to 13, 113), then tighten the No. 3 locking bolt (13 to 11, 111), then tighten the No. 7 locking bolt (17 to 15, 115), then tighten the No. 2 locking bolt (12 to 10, 110), then tighten the No. 8 locking bolt (18 to 16, 116), then tighten the No. 4 locking bolt (14 to 12, 112), then tighten again, and finally tighten the No. 6 locking bolt (16 to 14, 114). This design effectively balances the mechanical load.

[0063] In one possible implementation, the locking unit is tightened by five increments of torque, wherein the first torque is manually pre-tightened and the last torque is 200-250 N·m. In the above embodiment, the locking bolt 1 is tightened in five steps. The first step is to tighten it directly by hand until there is no gap, but the middle seat plate 5 and the top plate 6 must be kept parallel.

[0064] The second time, a torque wrench was manually used to adjust the torque to 70 N·m-90 N·m to begin tightening bolt 1, while keeping the middle seat plate 5 parallel to the top plate 6;

[0065] The third time, a torque wrench was manually used to adjust the torque to 130 N·m-150 N·m to begin tightening bolt 1, while keeping the middle seat plate 5 parallel to the top plate 6;

[0066] The fourth time, a torque wrench was manually used to adjust the torque to 190 N·m-210 N·m to begin tightening bolt 1, while keeping the middle seat plate 5 parallel to the top plate 6;

[0067] For the fifth time, tighten until jack 4 is not under stress, and tighten the locking bolt 1 to a final torque of 200 N·m-220 N·m.

[0068] In this embodiment, the torque adjusted by the second manual force wrench is preferably 80 N·m, the torque adjusted by the third manual force wrench is preferably 140 N·m, and the torque adjusted by the fourth manual force wrench is preferably 200 N·m. This application does not impose specific limitations on these adjustments.

[0069] Thirdly, the present invention also provides a pile foundation underpinning system, comprising:

[0070] At least two support piles 7, each of which is equipped with a corresponding lifting device;

[0071] The base plate 2 of the jacking device is fixed to the top of the corresponding replacement pile 7, and the top plate 6 is anchored to the bottom of the original structure. In this embodiment, the mechanical pre-tightening force generated by the locking bolt 1 permanently replaces the load-bearing process of the jack 4. All of these processes are manually tightened by hand using tools. During construction, the worker's operating clearance is 800mm, the overall operating space is suitable, and it is simpler to improve the worker's work efficiency.

[0072] Please refer to the detailed structure. Figure 4 The present invention comprises six replacement piles 7, each with a diameter of 1.5m and a length of 50m. Each pile is equipped with a corresponding lifting device. The preset load of each lifting device is set differently according to the bearing capacity of the corresponding replacement pile 7. The bearing capacity of each of the six replacement piles 7 is shown in the figure below:

[0073] Station number Lifting load A pile top 4833.82kN B pile top 5128.55kN C pile top 5297.14kN D pile top 4018.98kN E pile top 3724.24kN F pile top 3429.51kN

[0074] In one possible implementation, the tightening operations of the locking bolts 1 of adjacent lifting devices are performed asynchronously to improve the overall stability of the replacement.

[0075] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A pile foundation active underpinning and jacking device, which is installed between the underpinning pile and the original structure, characterized in that, include: The base plate is fixedly connected to the top of the supporting pile; The column has multiple columns, and the multiple columns are vertically fixed to the base plate; The middle base plate is horizontally fixed to the top of the multiple columns and forms a frame structure with the columns and the base plate. A central through hole is provided at the center of the middle base plate. The top plate is located on the upper part of the middle seat plate and is anchored to the bottom of the original structure; A lifting drive assembly is disposed on the base plate and passes through the central through hole of the middle seat plate, for lifting the top plate; Multiple locking units are distributed circumferentially along the lifting drive assembly and movably mounted on the middle base plate, with the force-applying ends of the multiple locking units extending through the middle base plate toward the top plate.

2. The active pile foundation underpinning and jacking device according to claim 1, characterized in that, The lifting drive assembly includes a jack, the bottom of which is disposed on the base plate, and its output end passes through the central through hole of the middle seat plate and abuts against the top plate.

3. The active pile foundation underpinning and jacking device according to claim 1, characterized in that, The locking unit is a locking bolt, and its screw axis is perpendicular to the lower surface of the top plate.

4. The active pile foundation underpinning and jacking device according to claim 3, characterized in that, The number of locking bolts is 8-20, and a pressure gap is reserved between the top of the bolt and the lower surface of the top plate.

5. A method for active pile foundation replacement, employing the jacking device described in any one of claims 1-3, characterized in that, Including the following steps: S1. The jack applies a lifting force to the top plate until the preset load of the jack is reached; S2. Maintain the preset load of the jack, and alternately tighten each locking unit according to the preset sequence of symmetrical grouping, so that the pre-tightening force generated by the locking unit is transmitted to the top plate. S3. Apply torque to the locking unit in stages until the actual load on the jack is zero; S4. Remove the jack.

6. The active pile foundation replacement method according to claim 5, characterized in that, The symmetrical grouping order is as follows: among multiple locking bolts, two locking bolts of the same diameter that pass through the axis of the jack are symmetrical, and multiple locking bolts arranged in a counterclockwise direction between them form a group, and there are multiple symmetrical groups.

7. The active pile foundation replacement method according to claim 5, characterized in that, The locking unit is tightened by five increments of torque, with the first torque being a manual pre-tightening and the last torque being 200-250 N·m.

8. A pile foundation underpinning system, characterized in that, include: At least two support piles, each of which is equipped with a corresponding lifting device; The base plate of the lifting device is fixed to the top of the corresponding replacement pile, and the top plate is anchored to the bottom of the original structure.

9. The pile foundation underpinning system according to claim 8, characterized in that, The preset load of each jacking device is set differently according to the bearing capacity of the corresponding replacement pile.

10. The pile foundation underpinning system according to claim 9, characterized in that, The tightening of the locking bolts of adjacent lifting devices is performed asynchronously.

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