A method for reducing the resistance of pipe piles around the basement to the settlement of the surrounding soil

Abstract

The present invention discloses a method for reducing the resistance of pipe piles around the basement to the settlement of the surrounding soil, which relates to the field of construction technology and includes a mechanism for reducing the resistance to the settlement of the surrounding soil and abandoned pipe piles; the mechanism for reducing the resistance to the settlement of the surrounding soil is composed of a precast concrete pipe, a precast reinforced concrete slab and foundation sand; by finding the piles, filling sand, pressing the precast concrete pipe, backfilling earthwork to stabilize the precast concrete pipe, plastering, covering the precast concrete pipe with the precast reinforced concrete slab and finally backfilling earthwork to the ground surface to restore the ground; setting up the mechanism for reducing the resistance of the surrounding soil to the settlement of the surrounding soil can effectively control the settlement speed of the ground above the abandoned pipe piles, make the settlement speed of the ground above the abandoned pipe piles consistent with that of the surrounding ground, avoid ground cracking caused by settlement differences, and solve the problem that the settlement speed of the ground above the pipe piles of abandoned tower cranes, passenger and freight elevators, and other structure foundations is inconsistent with that of the surrounding ground, resulting in easy damage to the ground of municipal and garden supporting facilities.

Description

Technical Field

[0001] The present invention relates to the field of construction technology, and particularly to a method for reducing the resistance of pipe piles around the basement to the settlement of surrounding soil bodies. Background Art

[0002] In most current constructions, before building the main building, pipe piles for carrying tower cranes of the building need to be driven outside the foundation of the main building, and then the tower crane foundation is poured on the pipe piles. After the main building starts the main stacking construction, the tower crane is installed on the tower crane foundation. After the main building is completed, the tower crane is demolished, and the pipe pile foundation is abandoned on the open ground. After the main building is completed, the surrounding open spaces will be built into gardens, green belts, sidewalks or squares, and the abandoned tower crane pipe pile foundations that are not demolished will also be buried under the concrete ground base layers of the built gardens, green belts, sidewalks or squares.

[0003] With the periodic pressure of rainwater and the ground and the movement of soil flow, the ground of the built gardens, squares, pedestrian roads or vehicle roads will settle. Among them, the reasons for the settlement can be understood from two aspects: natural factors and human factors.

[0004] (1) Natural factors mainly include natural disasters such as earthquakes, landslides, and collapses, as well as the ground elevation caused by crustal movements. Crustal movements will cause some places to rise and other places to fall, and the decomposition of organic matter in the soil will also cause the formation to compress.

[0005] (2) Human factors mainly include human activities such as excessive extraction of groundwater, mining of solid minerals, and extraction of oil and natural gas, which will all cause ground settlement. In addition, human engineering and economic activities such as excavation of slopes, landfill of garbage, and improper construction such as driving piles and pouring concrete without taking effective technical measures will also cause ground settlement.

[0006] However, due to the existence of previously abandoned tower crane pipe piles in some areas, and the bearing capacity is high where there are pipe pile foundations, the settlement speed of the soil above the pipe pile foundation is very slow, and the settlement speed of the ground above the pipe pile foundation is inconsistent with the settlement speed of the surrounding ground, resulting in uneven, cracked or damaged ground.

[0007] The common practice in the garden construction industry is to replace the soil on the top of the pipe pile foundation, blast and remove a certain length of the pipe pile, or directly backfill the soil without treatment on the abandoned pipe pile foundation; currently, according to the follow-up records in the later stage of garden construction, such solutions will all cause the soil, roads, pipe networks and other structures and facilities above the top of the pipe pile to be arched and damaged when the ground settles as a whole because they do not settle synchronously with the surrounding ground, and ultimately cannot be used normally.

[0008] Therefore, for the municipal and garden supporting facilities around the building, it is particularly prominent to prevent the problem that the later settlement speed of the tower crane pipe pile foundation is inconsistent with the surrounding ground settlement speed, which affects the normal use of the surrounding ground.

[0009] In summary, it is found that the existing technology has at least the following technical problems:

[0010] The ground settlement speed above the pipe piles of abandoned tower cranes, passenger and freight elevators, and other structures is inconsistent with the surrounding ground, resulting in the problem that the ground of municipal and garden supporting facilities is easily damaged. Summary of the Invention

[0011] The purpose of the present invention is to provide a method for reducing the resistance of pipe piles around the basement to the settlement of surrounding soil, so as to solve the problem that the ground settlement speed above the pipe piles of abandoned tower cranes, passenger and freight elevators, and other structures is inconsistent with the surrounding ground, resulting in the problem that the ground of municipal and garden supporting facilities is easily damaged.

[0012] The many technical effects that can be produced by the preferred technical solutions among the many technical solutions provided by the present invention are described in detail below.

[0013] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0014] The present invention provides a method for reducing the resistance of pipe piles around the basement to the settlement of surrounding soil, including a mechanism for reducing the resistance to the settlement of surrounding soil for controlling the settlement speed of the soil and ground above the abandoned pipe piles and the abandoned pipe piles below the ground settlement speed to be controlled; the mechanism for reducing the resistance to the settlement of surrounding soil is composed of precast concrete pipes, precast reinforced concrete slabs, and foundation sand;

[0015] It includes the following construction steps:

[0016] S1: Locate the position of the abandoned pipe pile foundation, excavate the surface, and dig to a depth of 3 meters below the top surface of the abandoned pipe pile, and the diameter of the excavation area is 4 times the diameter of the abandoned pipe pile;

[0017] S2: Level the bottom of the excavation area;

[0018] S3: Fill the excavation area with the foundation sand until the foundation sand is flush with the top surface of the abandoned pipe pile;

[0019] S4: Lower the precast concrete pipe into the excavation area, so that the precast concrete pipe sleeves outside the abandoned pipe pile, and the abandoned pipe pile is in the central area of the precast concrete pipe; the length of the lower precast concrete pipe is 2.5 - 3 meters;

[0020] S5: Press the precast concrete pipe into the foundation sand to a depth of one-fifth of the length of the precast concrete pipe, so that there is also foundation sand between the precast concrete pipe and the abandoned pipe pile, and leave a cavity between the top surface of the precast concrete pipe and the top surface of the abandoned pipe pile;

[0021] S6: Stabilize the precast concrete pipe and backfill the soil between the precast concrete pipe and the excavation area until it is flush with the top surface of the precast concrete pipe;

[0022] S7: Apply a layer of cement mortar to the top surface of the precast concrete pipe;

[0023] S8: Cover the top surface of the precast concrete pipe with the precast reinforced concrete slab, and the area of the precast reinforced concrete slab is larger than the cross-sectional area of the precast concrete pipe;

[0024] S9: Backfill the soil on the precast reinforced concrete slab to the ground surface and compact it;

[0025] The cavity left between the top surface of the precast concrete pipe and the top surface of the abandoned pipe pile is used to reserve space for ground settlement, so that the ground settlement speed above the abandoned pipe pile is consistent with the ground settlement speed of the surrounding area.

[0026] In one embodiment, it further includes a plurality of satellite traction mechanisms. The satellite traction mechanism includes a pile core, a bearing plate, a collar, and a first pulling rope. Connecting ear plates are provided on the outer wall surface of the collar and the lower end surface of the precast reinforced concrete slab. In step S1, outside a circle with a radius of 8 meters from the excavation area, an excavation area is 12 - 15 times the area of the precast reinforced concrete slab, down to a satellite area 6.5 meters below the top surface of the abandoned pipe pile. Insert the pile core with a length of at least 4 meters into the bottom of the satellite area with its tapered end at least 1 meter below the bottom. Slip the collar over the pile core so that the collar lands on the bottom of the satellite area, and rotate the ear plate of the collar to face the ear plate of the precast reinforced concrete slab. Excavate a first trench along the straight-line path from the ear plate of the collar to the ear plate of the precast reinforced concrete slab. The depth of the first trench corresponds to the depth of the satellite area. Place the first pulling rope in the first trench and fix the two ends of the first pulling rope to the ear plates of the collar and the precast reinforced concrete slab respectively. Backfill the satellite area and the first trench with soil to the top surface of the pile core. Place the bearing plate on the top surface of the pile core and fix the pile core to the bearing plate. Backfill the bearing plate and the first trench with soil to the ground surface and compact it. After the settlement space reserved in the precast concrete pipe is compressed, the satellite traction mechanism bears the soil pressure above it by means of the bearing plate. A plurality of the satellite traction mechanisms are combined and apply a downward pulling force to the abandoned pipe pile through their respective collars and first pulling ropes. Under the action of the pulling force, the abandoned pipe pile gradually sinks.

[0027] In one embodiment, the first pulling rope connects the ear plates of the collar and the precast reinforced concrete slab in a pre-tensioned manner.

[0028] In one embodiment, at least 8 satellite traction mechanisms are provided and are evenly arranged around the axis of the mechanism for reducing and resisting peripheral soil settlement.

[0029] In one embodiment, a second trench is excavated between adjacent satellite areas, and a second pulling rope is placed in the second trench. The two ends of the second pulling rope are connected to the ear plates of two adjacent collars in a pre-tensioned manner.

[0030] In one embodiment, wing plates are provided on two adjacent surfaces of the bearing plate, and the two wing plates face the mechanism for reducing and resisting peripheral soil settlement. The wing plates are used to prevent the pile core and the bearing plate from inclining into the mechanism for reducing and resisting peripheral soil settlement when the collar applies a pulling force to the first pulling rope.

[0031] In one embodiment, the pile core, the bearing plate, and the wing plate are all precast concrete components, wherein the bearing plate and the wing plate are integrally cast; a threaded rod is provided at the axis of the pile core, and a connecting through-hole is provided at the center of the bearing plate; when the pile core and the bearing plate are assembled, the threaded rod is passed through the connecting through-hole, and the pile core and the bearing plate are locked by nuts.

[0032] In one embodiment, a plurality of the satellite traction mechanisms arranged around a single abandoned pipe pile form a group of pipe pile sinking groups; a third pulling rope is further included, and a group of pipe pile sinking groups are respectively arranged for each adjacent abandoned pipe pile, and the multiple groups of pipe pile sinking groups are connected by the third pulling rope; both ends of the third pulling rope are respectively connected to the ear plates of the adjacent collars.

[0033] In one embodiment, the area of the bearing plate is 12 - 15 times the area of the precast reinforced concrete slab.

[0034] In one embodiment, the thickness of the precast reinforced concrete slab is at least 150 mm, and it is cast with concrete having a grade of at least C35.

[0035] The beneficial effects of the present invention are as follows:

[0036] First, by providing a mechanism for reducing and resisting the settlement of the surrounding soil above the abandoned pipe pile, the settlement speed of the ground above the abandoned pipe pile is effectively controlled, so that the settlement speed of the ground above the abandoned pipe pile is consistent with that of the surrounding ground; in the first ground synchronous settlement stage, the damage caused by the settlement difference to the municipal and garden supporting facilities is avoided. This design of ground synchronous settlement in different regions significantly improves the stability and safety of the municipal and garden supporting facilities and the ground.

[0037] Second, the present invention utilizes the precast concrete pipe and the foundation sand to form a buffer structure, wherein the foundation sand, as a filling material, has good compressive resistance and uniform settlement performance. By filling the foundation sand between the precast concrete pipe and the abandoned pipe pile, the direct action of the ground pressure on the abandoned pipe pile is further alleviated, and the risk of uneven ground settlement is reduced.

[0038] Third, by using precast concrete pipes and precast reinforced concrete slabs in the construction, the efficiency of the construction process and the standardization of the materials are ensured. Such prefabricated components reduce the complexity of on-site processing, shorten the construction period, and at the same time improve the construction quality and reliability. And local materials can be used, and the precast concrete pipe can also be replaced by a concrete drain pipe; in addition, the concrete material has a long service life, enhancing the durability of the entire structure.

[0039] During the construction process, there are multiple protection measures. Mortar is plastered on the top of the precast concrete pipe and a precast reinforced concrete slab is covered to prevent soil from being squeezed into the gap between the precast concrete pipe and the precast reinforced concrete slab under the pressure of the ground, thereby preventing erosion and reducing the cavity reserved in the inner wall of the precast concrete pipe for ground settlement, further enhancing the synchronous settlement time of the ground above the abandoned pipe pile and the surrounding ground. By backfilling the soil on the precast reinforced concrete slab to the ground surface and compacting it, not only the soil layer on the ground surface is restored, but also the flatness and stability of the ground surface are ensured, avoiding the phenomenon of ground depression or collapse caused by uneven settlement.

[0040] Finally, a cavity is reserved between the top surface of the precast concrete pipe and the top surface of the abandoned pipe pile, providing a buffer space for ground settlement, avoiding excessive pressure accumulation of the concrete stress on the ground above the abandoned pipe pile due to insufficient settlement, thereby effectively enhancing the integrity of the concrete on the ground above the abandoned pipe pile and avoiding ground cracking. This design concept has strong adaptability and is especially suitable for foundation treatment under complex geological conditions on the periphery of the basement.

[0041] In summary, the present invention significantly improves the settlement integrity, safety and uniformity of the ground above the abandoned pipe pile and the surrounding ground, effectively reduces the impact of the abandoned pipe pile on municipal and garden supporting facilities, and has wide engineering application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the technical solutions of the present invention, the drawings required for the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0043] Figure 1 is a schematic cross-sectional structure diagram of the mechanism for reducing and resisting the settlement of the surrounding soil in the first embodiment of the present invention;

[0044] Figure 2 is a schematic top view structure diagram of the circular precast reinforced concrete slab in the first embodiment of the present invention;

[0045] Figure 3 is a schematic top view structure diagram of the square precast reinforced concrete slab in the first embodiment of the present invention;

[0046] Figure 4 is a schematic cross-sectional structure diagram of the mechanism for reducing and resisting the settlement of the surrounding soil and the satellite traction mechanism in the second embodiment of the present invention;

[0047] Figure 5 is a schematic top view structure diagram of the mechanism for reducing and resisting the settlement of the surrounding soil and the satellite traction mechanism in the second embodiment of the present invention;

[0048] Figure 6 It is a top - view structural schematic diagram of multiple pipe - pile sinking groups in the third embodiment of the present invention.

[0049] Among them, the reference numerals are as follows:

[0050] 1. Mechanism for reducing the resistance of surrounding soil to settlement; 11. Prefabricated concrete pipe; 12. Prefabricated reinforced concrete slab; 13. Foundation sand;

[0051] 2. Excavation area; 21. Earthwork;

[0052] 3. Satellite traction mechanism; 31. Pile core; 32. Bearing plate; 321. Wing plate; 33. Collar; 34. First pull - rope; 35. Ear plate;

[0053] 4. Second pull - rope;

[0054] 5. Pipe - pile sinking group; 51. Third pull - rope;

[0055] 6. Abandoned pipe - pile;

[0056] 7. Ground. Detailed implementation manners

[0057] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention.

[0058] A method for reducing the resistance of pipe - piles outside the basement to the settlement of surrounding soil is provided in the detailed implementation manners, including a mechanism for reducing the resistance of surrounding soil to settlement and an abandoned pipe - pile; the mechanism for reducing the resistance of surrounding soil to settlement is composed of a prefabricated concrete pipe, a prefabricated reinforced concrete slab, and foundation sand; by finding the pile, filling sand, pressing the prefabricated concrete pipe, backfilling earthwork to stabilize the prefabricated concrete pipe, plastering, covering the prefabricated concrete pipe with the prefabricated reinforced concrete slab, and finally backfilling earthwork to the ground surface to restore the ground; setting up the mechanism for reducing the resistance of surrounding soil to settlement can effectively control the ground settlement speed above the abandoned pipe - pile, making the ground settlement speed above the abandoned pipe - pile consistent with that of the surrounding ground, and avoiding ground cracking caused by settlement differences; effectively solving the problem that the ground settlement speed above the pipe - piles of abandoned tower cranes, goods and passenger elevators, and other structure foundations is inconsistent with that of the surrounding ground, resulting in easy damage to the ground of municipal and garden supporting facilities.

[0059] In addition, all the contents of the configurations shown in the following embodiments are not limited to those necessary for the solution of the invention described in the claims.

[0060] The first embodiment of the method for reducing the resistance of pipe - piles outside the basement to the settlement of surrounding soil is as follows Figures 1 to 3As shown in the figure, it includes a mechanism 1 for reducing and resisting the settlement of the surrounding soil to control the settlement speed of the soil mass 21 above the abandoned pipe pile 6 and the ground 7, and the abandoned pipe pile 6 below the ground 7 whose settlement speed is to be controlled; the mechanism 1 for reducing and resisting the settlement of the surrounding soil is composed of a precast concrete pipe 11, a precast reinforced concrete slab 12 and a foundation sand 13.

[0061] It includes the following construction steps:

[0062] S1: Locate the foundation position of the abandoned pipe pile 6, excavate the surface of the ground, and dig to a depth of 3 meters below the top surface of the abandoned pipe pile 6, and the diameter of the excavation area 2 is 4 times the diameter of the abandoned pipe pile 6;

[0063] S2: Level the bottom of the excavation area 2;

[0064] S3: Fill the excavation area 2 with the foundation sand 13 until the foundation sand 13 is flush with the top surface of the abandoned pipe pile 6;

[0065] S4: Lower the precast concrete pipe 11 into the excavation area 2 so that the precast concrete pipe 11 is sleeved outside the abandoned pipe pile 6 and the abandoned pipe pile 6 is located in the central area of the precast concrete pipe 11; the length of the lower precast concrete pipe 11 is 2.5 - 3 meters;

[0066] S5: Press the precast concrete pipe 11 into the foundation sand 13, and the pressing depth is one-fifth of the length of the precast concrete pipe 11, so that there is also foundation sand 13 between the precast concrete pipe 11 and the abandoned pipe pile 6, and there is a cavity left between the top surface of the precast concrete pipe 11 and the top surface of the abandoned pipe pile 6;

[0067] S6: Stabilize the precast concrete pipe 11, and backfill the soil mass 21 between the precast concrete pipe 11 and the excavation area 2 until it is flush with the top surface of the precast concrete pipe 11;

[0068] S7: Apply a layer of cement mortar on the top surface of the precast concrete pipe 11;

[0069] S8: Cover the top surface of the precast concrete pipe 11 with the precast reinforced concrete slab 12, and the area of the precast reinforced concrete slab 12 is larger than the cross-sectional area of the precast concrete pipe 11;

[0070] S9: Backfill the soil mass 21 on the precast reinforced concrete slab 12 to the ground surface and compact it;

[0071] The cavity left between the top surface of the precast concrete pipe 11 and the top surface of the abandoned pipe pile 6 is used to reserve a space for the settlement of the ground 7, so that the settlement speed of the ground 7 above the abandoned pipe pile 6 is consistent with the settlement speed of the surrounding ground 7.

[0072] For the first embodiment of the method for reducing the resistance of the pipe piles around the basement to the settlement of the surrounding soil in the present invention, the settlement reduction mechanism 1 for resisting the settlement of the surrounding soil and the construction method for promoting the settlement of the ground 7 above the abandoned pipe piles 6 are provided; firstly, by arranging the settlement reduction mechanism 1 for resisting the settlement of the surrounding soil above the abandoned pipe piles 6, the settlement speed of the ground 7 above the abandoned pipe piles 6 is effectively controlled, so that the settlement speed of the ground 7 above the abandoned pipe piles 6 is consistent with that of the surrounding ground 7; in the first ground 7 synchronous settlement stage, the damage caused by the settlement difference to the municipal and garden supporting facilities is avoided. This design of synchronous settlement of the ground 7 in different regions significantly improves the stability and safety of the municipal and garden supporting facilities and the ground 7.

[0073] Secondly, the present invention uses the precast concrete pipe 11 and the foundation sand 13 to form a buffer structure, where the foundation sand 13 is used as a filling material and has good compressive resistance and uniform settlement performance. By filling the foundation sand 13 between the precast concrete pipe 11 and the abandoned pipe piles 6, the direct action of the ground 7 pressure on the abandoned pipe piles 6 is further alleviated, and the risk of uneven settlement of the ground 7 is reduced.

[0074] Thirdly, by using the precast concrete pipe 11 and the precast reinforced concrete slab 12 in the construction, the efficiency of the construction process and the standardization of the materials are ensured. Such prefabricated components reduce the complexity of on-site processing, shorten the construction period, and at the same time improve the construction quality and reliability. And local materials can be used, and the precast concrete pipe 11 can also be replaced by a concrete drain pipe; in addition, the concrete material has a long service life, enhancing the durability of the entire structure.

[0075] During the construction process, there are multiple protection measures. Mortar is plastered on the top end of the precast concrete pipe 11 and the precast reinforced concrete slab 12 is covered to prevent the soil from being squeezed into the gap between the precast concrete pipe 11 and the precast reinforced concrete slab 12 under the pressure of the ground 7, thereby preventing erosion and reducing the cavity reserved in the inner wall of the precast concrete pipe 11 for the settlement of the ground 7, further enhancing the time for the synchronous settlement of the ground 7 above the abandoned pipe piles 6 and the surrounding ground 7. By backfilling the soil mass 21 on the precast reinforced concrete slab 12 to the ground surface and compacting it, not only the soil layer on the surface of the ground 7 is restored, but also the flatness and stability of the ground surface are ensured, avoiding the depression or collapse of the ground 7 caused by uneven settlement.

[0076] Finally, a cavity is reserved between the top end surface of the precast concrete pipe 11 and the top end surface of the abandoned pipe piles 6 to provide a buffer space for the settlement of the ground 7, avoiding the excessive pressure accumulation of the concrete stress on the ground 7 above the abandoned pipe piles 6 due to insufficient settlement, thereby effectively improving the integrity of the concrete on the ground 7 above the abandoned pipe piles 6 and avoiding the cracking of the ground 7. This design concept has strong adaptability and is especially suitable for the foundation treatment under complex geological conditions around the basement.

[0077] In summary, the present invention significantly improves the integrity, safety, and uniformity of the settlement of the ground 7 above the abandoned pipe pile 6 and the surrounding ground 7, effectively reduces the impact of the abandoned pipe pile 6 on municipal and garden supporting facilities, and has broad engineering application value.

[0078] In addition, as Figure 2 and Figure 3 shown, the shape of the precast reinforced concrete slab 12 can be a square slab or a circular slab. The precast concrete pipe 11 can be a concrete drainage pipe; this enables the mechanism 1 for reducing the resistance to the settlement of the surrounding soil to have strong adaptability.

[0079] The second embodiment of the method for reducing the resistance of the pipe piles on the periphery of the basement to the settlement of the surrounding soil is as Figure 4 and Figure 5 shown. The difference between this embodiment and the first embodiment is that it further includes a plurality of satellite traction mechanisms 3. The satellite traction mechanism 3 includes a pile core 31, a bearing plate 32, a collar 33, and a first pulling rope 34; connecting ear plates 35 are provided on the outer wall surface of the collar 33 and the lower end surface of the precast reinforced concrete slab 12; in step S1, outside a circle with a radius of 8 meters around the excavation area 2, an excavation area with an area 12 - 15 times that of the precast reinforced concrete slab 12 is excavated to a depth of 6.5 meters below the top surface of the abandoned pipe pile 6 in the satellite area; a pile core 31 with a length of at least 4 meters is inserted with its tapered end at least 1 meter below the bottom end of the satellite area; the collar 33 is sleeved outside the pile core 31 so that the collar 33 falls on the bottom end of the satellite area, and the ear plate 35 of the collar 33 is rotated to face the ear plate 35 of the precast reinforced concrete slab 12; along the straight-line path from the ear plate 35 of the collar 33 to the ear plate 35 of the precast reinforced concrete slab 12, a first trench is excavated, and the depth of the first trench corresponds to the depth of the satellite area; the first pulling rope 34 is placed in the first trench, and both ends of the first pulling rope 34 are fixedly connected to the ear plate 35 of the collar 33 and the ear plate 35 of the precast reinforced concrete slab 12 respectively; the satellite area and the first trench are backfilled with soil 21 to the top surface of the pile core 31; the bearing plate 32 is placed on the top surface of the pile core 31 and the pile core 31 is fixedly connected to the bearing plate 32; the bearing plate 32 and the first trench are backfilled with soil 21 to the ground surface and compacted; after the settlement space reserved in the precast concrete pipe 11 is compressed, the satellite traction mechanism 3 bears the pressure of the soil 21 above it by means of the bearing plate 32, and a plurality of satellite traction mechanisms 3 are combined and apply a downward pulling force to the abandoned pipe pile 6 through their respective collars 33 and first pulling ropes 34, and the abandoned pipe pile 6 gradually sinks under the action of the pulling force.

[0080] Among them, the pile core 31, the bearing plate 32 and the wing plate 321 are all precast concrete components, and the bearing plate 32 and the wing plate 321 are integrally cast; a threaded rod is provided at the axis of the pile core 31, and a connection through hole is provided at the center of the bearing plate 32; when the pile core 31 and the bearing plate 32 are assembled, the threaded rod is passed through the connection through hole, and the pile core 31 and the bearing plate 32 are locked by nuts.

[0081] And the first stay rope 34 is connected to the ear plate 35 of the collar 33 and the ear plate 35 of the precast reinforced concrete slab 12 in a pre-tensioned manner.

[0082] During application, when the satellite traction mechanism 3 is embedded, the first stay rope 34 is connected to the ear plate 35 of the collar 33 and the ear plate 35 of the precast reinforced concrete slab 12 in a pre-tensioned manner. The collar 33 is sleeved on the pile core 31, and the collar 33 can slide on the pile core 31. As the reserved settlement space in the precast concrete pipe 11 of the peripheral soil settlement reduction mechanism 1 disappears and enters the second ground 7 synchronous settlement stage, the collar 33 slides upward as the bearing plate 32 and the pile core 31 sink, reaches below the bearing plate 32. Finally, under the limitation of the bearing plate 32 and the pile core 31, the collar 33 and the stay rope apply a downward pulling force to the precast reinforced concrete slab 12 of the peripheral soil settlement reduction mechanism 1. Through the peripheral soil settlement reduction mechanism 1, the vertical downward pulling forces provided by the multiple satellite traction mechanisms 3 are transmitted to the abandoned pipe pile 6, so that the abandoned pipe pile 6 gradually sinks during the second ground 7 synchronous settlement stage, reducing the impact on municipal and garden supporting facilities caused by the asynchronous settlement speed between the abandoned pipe pile 6 and the surrounding ground 7 after entering the second stage.

[0083] As one of the optional implementation manners,

[0084] Regarding the number of the above-mentioned satellite traction mechanisms 3 that can provide sufficient pulling force to enable the abandoned pipe pile 6 to sink slowly and gradually, for example, Figure 5 As shown, at least 8 satellite traction mechanisms 3 are provided and are evenly arranged around the axis of the peripheral soil settlement reduction mechanism 1.

[0085] Among them, the area of the bearing plate 32 is 12 - 15 times the area of the precast reinforced concrete slab 12. The thickness of the precast reinforced concrete slab 12 is at least 150 mm and is cast with concrete having a grade of at least C35.

[0086] During application, 8 satellite traction mechanisms 3 can make a pipe pile with a target diameter of 300 - 500 mm and a length of 20 - 30 meters; under the vertical downward pulling force exerted on the abandoned pipe pile 6 by the satellite traction mechanism 3 provided by geological subsidence and ground 7 dynamic pressure, the target abandoned pipe pile 6 sinks as synchronously as possible with the ground 7.

[0087] Regarding the additional structure of the above-mentioned bearing plate 32 and the second guy rope 4, preventing the single bearing plate 32 and the pile core 31 from gradually tilting under the action of the tensile force of the first guy rope 34, the implementation example is as follows Figure 5 As shown, wing plates 321 are provided on two adjacent surfaces of the bearing plate 32, and the two wing plates 321 face the mechanism 1 for reducing the resistance to the settlement of the surrounding soil; when the collar 33 applies a tensile force to the first guy rope 34, the wing plates 321 are used to prevent the pile core 31 and the bearing plate 32 from tilting inward into the mechanism 1 for reducing the resistance to the settlement of the surrounding soil.

[0088] Specifically, a second trench is excavated between adjacent satellite areas, and a second guy rope 4 is placed in the second trench. The two ends of the second guy rope 4 are connected to the ear plates 35 of two adjacent collars 33 in a pre-tensioned manner.

[0089] During application, by providing the wing plates 321 on the bearing plate 32, the combination of the single bearing plate 32 and the pile core 31 is improved to maintain its own vertical supporting force, and initially prevent the combination of the single bearing plate 32 and the pile core 31 from twisting and tilting when applying a tensile force to the mechanism 1 for reducing the resistance to the settlement of the surrounding soil and the abandoned pipe pile 6; by connecting the combinations of multiple bearing plates 32 and pile cores 31 through the second guy rope 4, and adding the connection between the first guy rope 34 and the precast reinforced concrete slab 12, the multiple satellite traction mechanisms 3 can form an umbrella-shaped overall structure around the abandoned pipe pile 6, improving the integrity of the multiple satellite traction mechanisms 3, and restricting the single one as a whole, further preventing the combination of the single bearing plate 32 and the pile core 31 from twisting and tilting.

[0090] The third implementation example of the method for reducing the resistance of the pipe piles around the basement to the settlement of the surrounding soil is as follows Figure 6 As shown, the difference between this implementation example and the second implementation example is that the multiple satellite traction mechanisms 3 arranged around a single abandoned pipe pile 6 are a group of pipe pile sinking groups 5; it also includes a third guy rope 51. A group of pipe pile sinking groups 5 are respectively arranged for each adjacent abandoned pipe pile 6, and the multiple pipe pile sinking groups 5 are connected by the third guy rope 51; the two ends of the third guy rope 51 are respectively connected to the ear plates 35 of adjacent collars 33.

[0091] During application, (a) when there are multiple abandoned pipe piles 6 at the construction site, a group of pipe pile sinking groups 5 are provided on each of the multiple abandoned pipe piles 6. The bearing plates 32 and pile cores 31 of adjacent pipe pile sinking groups 5 can be connected to the ear plates 35 on the other side of the collar 33 through the third guy rope 51, so that the adjacent collars 33 can obtain tensile forces in at least two directions, preventing the bearing plate 32 and the pile core 31 from twisting and tilting, and at the same time enhancing the overall sinking force of the abandoned pipe pile 6.

[0092] (b) If the diameter and length of the abandoned pipe pile 6 are too large and exceed the pulling force that the pipe pile sinking group 5 can use to pull the abandoned pipe pile 6 to sink, then multiple pipe pile sinking groups 5 are jointly fixed by the third pulling rope 51, enabling the overall ground 7 covered to achieve overall settlement under the support of the abandoned pipe pile 6.

[0093] (c) When the area of the ground 7 that needs to control settlement is too large, the abandoned pipe pile 6 also has a certain covered area. For the ground 7 lacking the abandoned pipe pile 6, new pipe piles can be added, and then the soil settlement resistance reduction mechanisms 1 are all arranged. After all the pipe pile sinking groups 5 are arranged and then jointly connected by the third pulling rope 51, the ground 7 can be supported by combining the abandoned pipe pile 6 and the new pipe piles, making the ground 7 form a whole and also avoiding the damage to the municipal and garden supporting facilities caused by settlement differences.

[0094] The technical features of the above embodiments can be combined arbitrarily. For the sake of concise description, not all possible combinations of the technical features in the above embodiments are described.

Claims

1. A method for reducing the surrounding soil settlement by using pipe piles outside a basement, characterized in that: It includes a mechanism for reducing and resisting the settlement of surrounding soil for controlling the earthwork and ground settlement velocity above the abandoned pipe piles and the abandoned pipe piles below the ground settlement velocity to be controlled; The mechanism for reducing and resisting the surrounding soil settlement is composed of precast concrete pipes, precast reinforced concrete slabs and foundation sand; The construction steps include: S1: Find the location of the abandoned pipe pile foundation, excavate the ground surface, and excavate to a depth of 3 meters below the top surface of the abandoned pipe pile, and the diameter of the excavation area is 4 times the diameter of the abandoned pipe pile; S2: leveling the bottom of the excavation area; S3: Filling the foundation sand into the excavation area until the foundation sand is flush with the top surface of the abandoned pipe pile; S4: lowering the precast concrete pipe to the excavation area, so that the precast concrete pipe is sleeved outside the abandoned pipe pile, and the abandoned pipe pile is located in the center area of ​​the precast concrete pipe; the length of the lower precast concrete pipe is 2.5-3 meters; S5: Pressing the precast concrete pipe into the foundation sand to a depth of one fifth of the length of the precast concrete pipe, so that there is foundation sand between the precast concrete pipe and the abandoned pipe pile, and a cavity is left between the top end surface of the precast concrete pipe and the top end surface of the abandoned pipe pile; S6: Stabilize the precast concrete pipe, and backfill earth between the precast concrete pipe and the excavation area until the earth is flush with the top surface of the precast concrete pipe; S7: applying a layer of cement mortar to the top surface of the precast concrete pipe; S8: Covering the precast reinforced concrete slab on the top surface of the precast concrete pipe, the area of ​​the precast reinforced concrete slab is larger than the cross-sectional area of ​​the precast concrete pipe; S9: backfilling soil onto the prefabricated reinforced concrete slab to the ground surface and compacting it; The cavity left between the top end surface of the precast concrete pipe and the top end surface of the abandoned pipe pile is used to reserve space for ground settlement, so that the ground settlement speed above the abandoned pipe pile is consistent with the settlement speed of the surrounding ground; It also includes a plurality of satellite traction mechanisms, the satellite traction mechanisms including a pile core, a pressure plate, a collar and a first pull rope; the outer wall surface of the collar and the lower end surface of the prefabricated reinforced concrete slab are provided with connecting ear plates; In step S1, a satellite area is excavated at a radius of 8 meters from the excavation area, with an area of ​​12-15 times the area of ​​the prefabricated reinforced concrete slab, to a depth of 6.5 meters below the top surface of the abandoned pipe pile; Inserting the pile core having a length of at least 4 meters at a point at least 1 meter below the bottom end of the satellite area with the conical end of the pile core; Put the collar on the outside of the pile core so that the collar falls on the bottom of the satellite area, and rotate the ear plate of the collar to face the ear plate of the prefabricated reinforced concrete slab; excavating a first trench along a straight path from the ear plate of the collar to the ear plate of the prefabricated reinforced concrete slab, wherein the depth of the first trench corresponds to the depth of the satellite area; Placing the first draw rope in the first groove, so that two ends of the first draw rope are respectively connected and fixed to the ear plate of the ring and the ear plate of the prefabricated reinforced concrete slab; Backfilling the satellite area and the first trench with earth to the top surface of the pile core; Placing the pressure plate on the top surface of the pile core, and connecting and fixing the pile core to the pressure plate; backfilling earth on the pressure plate and the first groove to the ground surface and compacting it; After the settlement space reserved in the precast concrete pipe is compressed, the satellite traction mechanism bears the earth pressure above it with the help of the pressure plate, and multiple satellite traction mechanisms are combined to apply downward pulling force to the abandoned pipe pile through their respective rings and the first pull rope. The abandoned pipe pile gradually sinks under the pulling force.

2. The method for reducing the surrounding soil settlement by using pipe piles outside the basement according to claim 1 is characterized in that: The first pull rope connects the ear plate of the ring and the ear plate of the prefabricated reinforced concrete slab in a pre-tensioned manner.

3. The method for reducing the surrounding soil settlement by using pipe piles outside the basement according to claim 1 is characterized in that: At least eight satellite traction mechanisms are provided and are evenly arranged around the axis of the mechanism for reducing and resisting surrounding soil settlement.

4. The method for reducing the surrounding soil settlement by using pipe piles outside the basement according to claim 3 is characterized in that: A second groove is excavated between adjacent satellite areas, a second pull rope is placed in the second groove, and two ends of the second pull rope are connected to the ear plates of two adjacent rings in a pre-tensioned manner.

5. The method for reducing the surrounding soil settlement by using pipe piles outside the basement according to claim 4 is characterized in that: Wing plates are arranged on two adjacent surfaces of the pressure plate, and the two wing plates are arranged toward the mechanism for reducing and resisting the settlement of the surrounding soil; the wing plates are used to prevent the pile core and the pressure plate from tilting inward toward the mechanism for reducing and resisting the settlement of the surrounding soil when the ring applies tension to the first pull rope.

6. The method for reducing the surrounding soil settlement by using pipe piles outside the basement according to claim 5 is characterized in that: The pile core, the pressure bearing plate and the wing plate are all precast concrete components, wherein the pressure bearing plate and the wing plate are cast in one piece; The axis of the pile core is provided with a threaded rod, and the center of the pressure plate is provided with a connecting through hole; When the pile core is assembled with the pressure plate, the threaded rod is passed through the connecting through hole, and the pile core and the pressure plate are locked by a nut.

7. The method for reducing the surrounding soil settlement by using pipe piles outside a basement according to claim 4 is characterized in that: The plurality of satellite traction mechanisms arranged around a single abandoned pipe pile constitute a pipe pile sinking group; It also includes a third pull rope, each adjacent abandoned pipe pile is respectively arranged with a group of pipe pile sinking groups, and multiple pipe pile sinking groups are connected by the third pull rope; Two ends of the third pull rope are respectively connected to the ear plates of the adjacent rings.

8. The method for reducing the surrounding soil settlement by using pipe piles outside a basement according to claim 1 is characterized in that: The area of ​​the pressure-bearing plate is 12-15 times the area of ​​the prefabricated reinforced concrete slab.

9. The method for reducing the surrounding soil settlement by using pipe piles outside a basement according to claim 1 is characterized in that: The prefabricated reinforced concrete slab has a thickness of at least 150 mm and is cast using concrete with a grade of at least C35.

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