Small counter-force device for pre-pressing newly-added reinforced pile foundation

Abstract

The utility model relates to the technical field of bridge old pile foundation reinforcement, in particular to a small counter-force device for pre-pressing a newly-added reinforcement pile foundation, a reinforcement bearing platform fixedly connected with the old pile foundation is transversely arranged on the old pile foundation, and the two sides of the reinforcement bearing platform extend out of the old pile foundation to form connecting parts. A containing space for containing a part of the structure of the small counter-force device is formed in the connecting part, and new pile foundations embedded into the ground are pre-arranged on the two sides of the old pile foundation. The bearing mechanism is arranged on the connecting part and stretches across the containing space, and the pre-pressing mechanism is arranged at the top of the new pile foundation and used for pre-pressing the bearing mechanism so as to share part of dead load borne by the old pile foundation to the new pile foundation. The small counter-force device further comprises a temporary steel supporting piece which is cushioned between the new pile foundation and the bearing mechanism and used for replacing the pre-pressing mechanism or jointly stressed with the pre-pressing mechanism so as to share part of dead load borne by the old pile foundation to the new pile foundation. The problems that on-site construction difficulty is large, anchor piles need to be additionally constructed, the construction process is tedious, and the period is long are solved.

Description

【TECHNICAL FIELD]

[0001] The utility model relates to bridge old pile foundation reinforcing technical field, concretely relates to a small counterforce device for prepressing new reinforcing pile foundation.

【BACKGROUND TECHNIQUE]

[0002] With the sustained take-off of China's economy and the continuous deepening of urbanization process, bridge engineering has not only been a simple traffic tool, but also an important symbol of measuring a country's modernization construction and technical strength. However, for the economic and durable bridge, the stability of the pile foundation is essential. Pile foundation reinforcing technology is a branch derived to ensure the safety of pile foundation, which has developed for more than ten years. However, under the variable geographical environment and climate conditions in China, pile foundation reinforcing technology is facing many challenges, for example, under the complex geological conditions such as soft soil, marsh, rock fracture zone, etc., in order to ensure the stability of the pile foundation, the new pile foundation is often connected with the old pile foundation to form a whole row of piles, and a part of the dead load borne by the original pile foundation is often replaced to create a small counterforce device for prepressing the pile foundation under the soft soil foundation and narrow space. The present application makes full use of the reinforcing structure, the overall device specification is small, the structure is simple, the loading efficiency is high, the practicality is strong, and has wide application prospect.

[0003] In the prior art, the counterforce device for prepressing the pile foundation includes a heavy platform counterforce device, an anchor pile counterforce device and a ground anchor counterforce device. The heavy platform counterforce device is composed of a buttress, a main beam, a secondary beam and heavy objects, has the characteristics of simple erection and fast erection speed, and is the most common counterforce device in the pile foundation pretest at present, but it occupies a large space and has low loading efficiency. The anchor pile counterforce device is connected with the anchor pile to provide the counterforce, and the counterforce frame is lifted by the jack at the top of the pile to provide the counterforce by the connected anchor pile. This device is not limited by the site conditions and the loading tonnage, but it still needs to construct 1-2 anchor piles in addition to the engineering pile, which has complicated construction process and long construction period, and poor economy. The ground anchor counterforce device is suitable for small tonnage pile foundation, and the loading is convenient, but it has high requirement for the geological conditions of the foundation soil layer, and cannot provide effective anchoring on the soft soil foundation.

[0004] In view of the above technical problems, the utility model is hereby researched and proposed.

UTILITY MODEL CONTENTS

[0005] The utility model solves the technical problem to provide a small counterforce device for prepressing new reinforcing pile foundation, which can make full use of the reinforcing structure as an anchor by setting the bearing mechanism, the prepressing mechanism and the temporary steel support, without the need of constructing the anchor pile additionally, can facilitate the on-site construction, and effectively reduces the construction difficulty. The problems of large on-site construction difficulty, the need of constructing the anchor pile additionally, complicated construction process and long construction period are solved.

[0006] To solve the above technical problems, the utility model provides a small counterforce device for preloading of newly added reinforced pile foundation, the old pile foundation is provided with a reinforced pile cap fixedly connected thereto in the transverse direction, the reinforced pile cap extends out of the old pile foundation on both sides to form a connecting part, a receiving space for accommodating part of the structure of the small counterforce device is formed in the connecting part, and new pile foundations are embedded in the ground on both sides of the old pile foundation, the small counterforce device comprises a bearing mechanism arranged on the connecting part and crossing the receiving space and a preloading mechanism arranged on the top of the new pile foundation and preloading the bearing mechanism to distribute part of the dead load borne by the old pile foundation to the new pile foundation, and the small counterforce device further comprises a temporary steel support member inserted between the new pile foundation and the bearing mechanism to replace the preloading mechanism or to bear part of the dead load borne by the old pile foundation together with the preloading mechanism.

[0007] The small counterforce device for preloading of newly added reinforced pile foundation as described above, the bearing mechanism comprises a cross beam assembly matched with the preloading mechanism and a fixing member for detachably fixing the cross beam assembly on the connecting part.

[0008] The small counterforce device for preloading of newly added reinforced pile foundation as described above, the preloading mechanism comprises a jack arranged on the new pile foundation.

[0009] The small counterforce device for preloading of newly added reinforced pile foundation as described above, the preloading mechanism further comprises an upper stress diffusion steel plate, a force transmission steel and a lower stress diffusion steel plate arranged in sequence at the bottom of the jack.

[0010] The small counterforce device for preloading of newly added reinforced pile foundation as described above, the jack, the upper stress diffusion steel plate, the force transmission steel, the lower stress diffusion steel plate and the new pile foundation are coaxially arranged at the center.

[0011] The small counterforce device for preloading of newly added reinforced pile foundation as described above, the cross beam assembly comprises a pair of connecting cross beams connected with the connecting part and a bearing cross beam arranged between the two connecting cross beams, the bearing cross beam is arranged above the receiving space and abuts against the preloading mechanism, the two ends of the bearing cross beam are fixedly connected with the corresponding connecting cross beams, and the connecting cross beams are detachably connected with the connecting part through the fixing member.

[0012] The small counterforce device for preloading of newly added reinforced pile foundation as described above, the bearing cross beam and the connecting cross beam are fixedly connected in a welding manner.

[0013] The small counterforce device for preloading of newly added reinforced pile foundation as described above, the fixing member is a vertical anchor rod having a plurality of roots, the lower part of the vertical anchor rod is embedded in the connecting part and forms an integral whole with the connecting part, and the upper part of the vertical anchor rod is connected with the connecting cross beam.

[0014] The small counterforce device for preloading of newly added reinforced pile foundation as described above, the vertical anchor rod is made of a precision rolled threaded steel.

[0015] As described above, a small reaction device for preloading newly added fixed pile foundations has a gap between the connecting part and the crossbeam assembly to facilitate the removal of the preloading mechanism.

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

[0017] 1. The small reaction device applied for has a small overall size and is easy to load, making it very suitable for preloading of reinforced pile foundations in confined spaces.

[0018] 2. The small reaction device of this application has a simple structure, makes full use of the reinforcement structure as an anchor, does not require additional anchor pile construction, facilitates on-site construction, effectively reduces construction difficulty, and has good overall economic efficiency.

[0019] 3. The small reaction device of this application can be prefabricated in the factory and installed on site, which requires a short construction period and has the advantage of rapid construction.

[0020] 4. The pre-compression mechanism and crossbeam assembly in the small reaction device of this application can be disassembled and reused, which can reduce production costs. [Attached Image Description]

[0021] The specific embodiments of this utility model will be further described in detail below with reference to the accompanying drawings, wherein:

[0022] Fig. 1 This is a schematic diagram of the structure of this utility model.

[0023] Fig. 2 This is another structural schematic diagram of the load-bearing mechanism in this utility model.

[0024] Fig. 3 This is a schematic diagram of the pre-compression mechanism in this utility model.

[0025] In the diagram: 1. Old pile foundation; 2. Reinforced pile cap; 20. Connection part; 3. New pile foundation; 4. Bearing mechanism; 40. Crossbeam assembly; 400. Connecting crossbeam; 401. Bearing crossbeam; 41. Fixing component; 5. Preloading mechanism; 50. Jack; 51. Upper stress diffusion steel plate; 52. Force transmission steel; 53. Lower stress diffusion steel plate; 6. Temporary steel support component.

Detailed Implementation Methods

[0026] The embodiments of this utility model will now be described in detail with reference to the accompanying drawings.

[0027] like Figs. 1-3As shown, a kind of small counter-force device for prepressing new reinforced pile foundation, old pile foundation 1 is provided with reinforced cap 2 fixedly connected with it transversely, the two sides of reinforced cap 2 extend out of old pile foundation 1 to form connecting portion 20, connecting portion 20 is formed with accommodating space for accommodating part of structure of small counter-force device, the accommodating space is not shown in the figure, the two sides of old pile foundation 1 are provided with new pile foundation 3 embedded in ground, small counter-force device includes bearing mechanism 4 arranged on connecting portion 20 and across the accommodating space and prepressing mechanism 5 arranged on the top of new pile foundation 3 for prepressing bearing mechanism 4 to share part of dead load borne by old pile foundation 1 to new pile foundation 3, small counter-force device further includes temporary steel support 6 for being filled between new pile foundation 3 and bearing mechanism 4 to replace prepressing mechanism 5 or jointly stressed with prepressing mechanism 5 to share part of dead load borne by old pile foundation 1 to new pile foundation 3.Temporary steel support 6 adopts solid cube with Q235b material, thin steel plate (not shown in the figure) can be filled between upper and lower temporary steel support 6 to fill the gap, and temporary steel support 6 plays the role of replacing prepressing mechanism 5.

[0028] In the embodiment, when new pile foundation 3 and reinforced cap 2 are built, the following steps are taken for construction:

[0029] (1) According to whether the structure pile foundation construction needs to be excavated and the excavation depth according to the construction clearance under the bridge, the excavation depth should be controlled to be minimum.

[0030] (2) New pile foundation 3 is built, steel casing is followed to construct, and the steel casing should pass through silt layer, and rotary drilling is adopted for construction to avoid using punching to construct, and to avoid disturbance of new pile foundation 3 construction to original structure.

[0031] (3) New pile foundation 3 is poured, after drilling is completed, steel reinforcement should be placed as soon as possible to pour pile foundation concrete, in order to ensure the safety of old pile foundation 1, new pile foundation 3 should be drilled and poured one by one.

[0032] (4) After all pile foundation construction is completed, excavation or filling is carried out to the design elevation of new reinforced cap 2, and the new reinforced cap 2 is flattened, compacted and designed to be 10cm to 20cm thick C20 plain concrete below the design elevation of new reinforced cap 2, to ensure the reliability of connection between new reinforced cap 2 and original structure concrete. In addition, relative settlement during concrete solidification process needs to be strictly controlled, and the requirements are as follows: A, the bottom of reinforced cap 2 must be rammed to compactness not less than 95% before filling and pouring; B, the bottom of reinforced cap 2 cannot be disturbed during concrete solidification process.

[0033] (5) The connecting portion 20 of old pile foundation 1 and reinforced cap 2 is subjected to bar planting and surface treatment, and the steel reinforcement arrangement of reinforced cap 2 should not affect bar planting operation.

[0034] (6) Reinforced cap 2 concrete is poured, and after the strength of concrete reaches 90% of design value and the age is not less than seven days, formwork is removed, and foundation pit is backfilled.

[0035] It should be noted that in the above steps, when adding and reinforcing the foundation 2, space will be reserved to accommodate the preloading mechanism 5.

[0036] After the new pile foundation 3 and the reinforced pile cap 2 are constructed, a preloading mechanism 5 is installed on the top of the new pile foundation 3. Then, a bearing mechanism 4 is installed on the connecting part 20 to cooperate with the preloading mechanism 5. The preloading mechanism 5 preloads the bottom of the bearing mechanism 4 upwards. Once the set value is reached, a temporary steel support 6 is inserted. The temporary steel support 6 can then replace the preloading mechanism 5 in bearing the load or share the load with the preloading mechanism 5, transferring part of the dead load on the old pile foundation 1 to the new pile foundation 3. Concrete can then be poured into the pile head of the new pile foundation 3 to fill the space, making the new pile foundation 3, the reinforced pile cap 2, and the temporary steel support 6 a unified whole, thus reinforcing the old pile foundation 1. It should be noted that in this embodiment, the preloading mechanism 5 can be disassembled during concrete pouring for future use. However, due to the low cost of the preloading mechanism 5, it can also be left on the new pile foundation 3.

[0037] The small reaction device in this embodiment is compact in size and easy to load, making it ideal for preloading reinforced pile foundations in confined spaces. Furthermore, the small reaction device has a simple structure, fully utilizing the reinforcement structure as an anchor, eliminating the need for additional anchor piles, facilitating on-site construction, effectively reducing construction difficulty, and offering excellent overall economic benefits. In addition, the small reaction device can be prefabricated in the factory and installed on-site, requiring a short construction period and offering the advantage of rapid construction.

[0038] like Figs. 1 to 3 As shown, as a further embodiment, the bearing mechanism 4 includes a beam assembly 40 that cooperates with the pre-compression mechanism 5 and a fastener 41 for detachably fixing the beam assembly 40 to the connecting portion 20.

[0039] The crossbeam assembly 40 includes a pair of connecting crossbeams 400 connected to the connecting part 20 and a load-bearing crossbeam 401 erected between the two connecting crossbeams 400. The load-bearing crossbeam 401 is located above the accommodating space and abuts against the pre-compression mechanism 5. The two ends of the load-bearing crossbeam 401 are fixedly connected to the corresponding connecting crossbeams 400. The connecting crossbeams 400 are detachably connected to the connecting part 20 by fasteners 41. The load-bearing crossbeam 401 and the connecting crossbeams 400 are fixedly connected by welding.

[0040] The fixing member 41 is a vertical anchor rod and has multiple roots, the lower part of the vertical anchor rod is embedded in the connecting part 20 and forms an integral whole with the connecting part 20, and the upper part of the vertical anchor rod is connected with the connecting cross beam 400. The vertical anchor rod adopts a precision rolled threaded steel with a diameter of 32 mm, one end of which is embedded into the reinforced pile cap 2, and the other end is embedded into the concrete of the pile head part of the pile foundation, after the concrete is solidified, the cross beam assembly 40 can be disassembled and reused.

[0041] As shown in Figs. 1 to 3 , as a further scheme of the embodiment, the pre-pressing mechanism 5 comprises a jack 50 arranged on the new pile foundation 3, in the embodiment, the jack 50 is low in cost and high in stability, and can adapt to a smaller space.

[0042] As shown in Figs. 1 to 3 , as a further scheme of the embodiment, the pre-pressing mechanism 5 further comprises an upper stress diffusion steel plate 51, a force transmission steel 52 and a lower stress diffusion steel plate 53 arranged in sequence at the bottom of the jack 50, and the jack 50, the upper stress diffusion steel plate 51, the force transmission steel 52, the lower stress diffusion steel plate 53 and the new pile foundation 3 are coaxially arranged. By arranging the upper stress diffusion steel plate 51, the force transmission steel 52 and the lower stress diffusion steel plate 53, the jack 50 can be effectively supported, and the problem of insufficient height of the jack 50 is solved, and after jacking, the jack 50, the upper stress diffusion steel plate 51, the force transmission steel 52 and the lower stress diffusion steel plate 53 can be taken out without affecting the pouring of the concrete.

[0043] As shown in Fig. 1 , as a further scheme of the embodiment, the connecting part 20 and the cross beam assembly 40 have a space for taking out the pre-pressing mechanism 5. By arranging the space between the connecting part 20 of the cross beam assembly 40 and the reinforced pile cap 2, the jack 50, the upper stress diffusion steel plate 51, the force transmission steel 52 and the lower stress diffusion steel plate 53 in the pre-pressing mechanism 5 can be easily taken out, and the construction efficiency is effectively improved.

[0044] As shown in Figs. 1 to 3 , the utility model also provides a reinforcing method for pre-pressing and reinforcing old pile foundations, which uses the small counter-force device for pre-pressing new reinforced pile foundations described above, and comprises the following steps:

[0045] S1, presetting the new pile foundation 3 and the reinforced pile cap 2, new pile foundations 3 are newly built on both sides of the old pile foundation 1, the reinforced pile cap 2 is additionally arranged on the old pile foundation 1, the reinforced pile cap 2 and the old pile foundation 1 form an integral whole, the connecting part 20 is formed by extending the two sides of the reinforced pile cap 2 outward, the connecting part 20 reserves a containing space for containing the pre-pressing mechanism 5, and the fixing member 41 is preset on the connecting part 20, and the newly built new pile foundation 3 is located below the corresponding connecting part 20. The construction process of presetting the new pile foundation 3 and the reinforced pile cap 2 is carried out according to the above steps, and details are not repeated here.

[0046] S2, the small counter-force device is laid out, when the small counter-force device is laid out, the pre-pressing mechanism 5 is laid out first, the pre-pressing mechanism 5 is laid out at the center position of the top of the new pile foundation 3, then the bearing mechanism 4 is laid out, the crossbeam assembly 40 in the bearing mechanism 4 is connected with the fixing part 41 in S1, the crossbeam whole bearing mechanism 4 and the connecting part 20 form an integral whole, and the crossbeam assembly 40 spans the containing space and is located above the pre-pressing mechanism 5.

[0047] S3, the small counter-force device is started to make part of the dead load borne by the old pile foundation 1 be shared to the new pile foundation 3, when the small counter-force device is started, the pre-pressing mechanism 5 is started first, the pre-pressing mechanism 5 is lifted upwards to the crossbeam assembly 40, so that the new pile foundation 3 is pre-pressed, after the pre-pressing reaches a preset value, the cushioning temporary steel support 6 is used to replace the pre-pressing mechanism 5 or to share force with the pre-pressing mechanism 5 to make part of the dead load borne by the old pile foundation 1 be shared to the new pile foundation 3.

[0048] S4, the concrete is poured on the pile head of the new pile foundation 3, so that the bearing mechanism 4, the new pile foundation 3 and the reinforced pile cap 2 are connected into an integral whole. In this step, after the cushioning temporary steel support 6, the pre-pressing mechanism 5 can be disassembled and used next time. Because the pre-pressing mechanism 5 has a low cost, the pre-pressing mechanism 5 can also be left on the new pile foundation 3.

[0049] As a further scheme of the embodiment, after the poured concrete is shaped, the crossbeam assembly 40 is disassembled, and the crossbeam assembly 40 can be used next time after disassembly, thereby saving cost.

[0050] As a further scheme of the embodiment, in S4, when the reinforced pile cap 2 is pre-set, a steel bar reserved opening penetrating the containing space is reserved in the connecting part 20, and in S3, after the pre-pressing of the pre-pressing mechanism 5 is completed, the pre-pressing mechanism 5 is disassembled, the steel bar penetrating the containing space is implanted at the steel bar reserved opening, and the steel bar is arranged along the length direction of the reinforced pile cap 2. After the pre-pressing mechanism is disassembled, the steel bar is implanted, and after the steel bar is arranged, the connection strength between the new pile foundation 3 and the reinforced pile cap 2 can be strengthened. It needs to be noted that the steel bar reserved opening and the steel bar are not shown in the application.

[0051] The reinforcing method for reinforcing the old pile foundation by pre-pressing in the application relies on the small counter-force device in the application, and the old pile foundation 1 of the bridge is reinforced through the above steps, without the need of constructing anchor piles additionally, which can facilitate the on-site construction, effectively reduce the construction difficulty, and effectively improve the construction efficiency. The small counter-force device in the application can be prefabricated in the factory and installed on site, has a short construction period, and has the advantage of rapid construction.

Claims

1. A small-sized counterforce device for preloading a newly added reinforced pile foundation, a reinforcement pile cap (2) is transversely arranged on an old pile foundation (1) and fixedly connected thereto, the reinforcement pile cap (2) extends out of the old pile foundation (1) on both sides to form a connecting portion (20), a containing space for containing part of the structure of the small-sized counterforce device is formed in the connecting portion (20), and a new pile foundation (3) is embedded in the ground on both sides of the old pile foundation (1), characterized in that The small counterforce device comprises a bearing mechanism (4) arranged on the connecting part (20) and across the accommodating space, and a pre-pressing mechanism (5) arranged on the top of the new pile foundation (3) to pre-press the bearing mechanism (4) and share part of the dead load borne by the old pile foundation (1) to the new pile foundation (3), and further comprises a temporary steel support (6) filled between the new pile foundation (3) and the bearing mechanism (4) to replace the pre-pressing mechanism (5) or jointly bear the part of the dead load borne by the old pile foundation (1) to the new pile foundation (3).

2. The small-sized counterforce device for preloading of a newly added reinforced pile foundation according to claim 1, characterized in that The bearing mechanism (4) comprises a cross beam assembly (40) matched with the pre-pressing mechanism (5) and a fixing part (41) for detachably fixing the cross beam assembly (40) on the connecting part (20).

3. The small-sized counterforce device for preloading of newly added reinforced pile foundation according to claim 1, characterized in that The pre-pressing mechanism (5) comprises a jack (50) arranged on the new pile foundation (3).

4. The small-sized counterforce device for preloading of a newly added reinforced pile foundation according to claim 3, characterized in that The pre-pressing mechanism (5) further comprises an upper stress diffusion steel plate (51), a force transmission steel (52) and a lower stress diffusion steel plate (53) arranged in sequence at the bottom of the jack (50).

5. The small-sized counterforce device for preloading of a newly added reinforced pile foundation according to claim 4, characterized in that The center of the jack (50), the upper stress diffusion steel plate (51), the force transmission steel (52), the lower stress diffusion steel plate (53) and the new pile foundation (3) are coaxially arranged.

6. The small-sized counterforce device for preloading of a newly added reinforced pile foundation according to claim 2, characterized in that The cross beam assembly (40) comprises a pair of connecting cross beams (400) connected with the connecting part (20) and a bearing cross beam (401) erected between the two connecting cross beams (400), the bearing cross beam (401) is located above the accommodating space and abuts against the pre-pressing mechanism (5), the two ends of the bearing cross beam (401) are fixedly connected with the corresponding connecting cross beams (400), and the connecting cross beams (400) are detachably connected with the connecting part (20) through the connecting parts; 7. The small-sized reaction force device for preloading of a newly added reinforced pile foundation according to claim 6, characterized in that The bearing cross beam (401) and the connecting cross beam (400) are fixedly connected in a welding manner.

8. The small-sized counterforce device for preloading of a newly added reinforced pile foundation according to claim 5, characterized in that The fixing part (41) is a vertical anchor rod and has a plurality of vertical anchor rods, the lower part of the vertical anchor rod is pre-buried in the connecting part (20) and forms an integral whole with the connecting part (20), and the upper part of the vertical anchor rod is connected with the connecting cross beam (400).

9. The small-sized reaction force device for preloading of a newly added reinforced pile foundation according to claim 8, characterized in that The vertical anchor rod is made of a precision rolled threaded steel.

10. The small-sized counterforce device for preloading of a newly added reinforced pile foundation according to claim 5, characterized in that The connecting part (20) and the cross beam assembly (40) have a space for taking out the pre-pressing mechanism (5).

Images