Fabricated high-strength toughness composite precast column pile

Abstract

The application discloses an assembled high-strength toughness composite prefabricated stand column pile and belongs to the technical field of foundation pit supporting.The assembled high-strength toughness composite prefabricated stand column pile comprises a foundation pile section and a stand column section, the foundation pile section and the stand column section are assembled and connected through a bottom plate section, and the stand column sections are assembled and connected through support sections, so that the stand column sections are easily disassembled and 100% recycled in the foundation pit disassembling stage; meanwhile, the stand column section adopts a structural layer composite structure, which greatly reduces the steel consumption of the previous steel lattice column, greatly improves the strength, toughness and tensile strength of the stand column pile, can utilize a static pressure machine to press or top-press, the construction process is simpler, the construction efficiency is obviously improved, and the application range is more extensive; in addition, the bottom plate section and the support section are internally pre-buried with upper and lower layer bidirectional steel bar connectors, so that the connection firmness between the foundation pit bottom plate and the stand column pile and between the foundation pit supporting beam and the stand column pile is improved, and the stability of deep foundation pit supporting is ensured.

Description

TECHNICAL FIELD

[0001] The present application relates to a column pile for deep foundation pit support, more particularly to a prefabricated high-strength and ductile composite column pile. BACKGROUND

[0002] With the acceleration of urbanization and the deepening of underground space development, deep foundation pit engineering has become the core link of high-rise buildings, subway tunnels, underground comprehensive pipe galleries and other projects. At the same time, deep foundation pit engineering also faces multiple challenges such as complex stratum adaptation, green construction and intelligent construction. As a key vertical load-bearing component in the foundation pit support system, the performance index of the column pile is directly related to the safety of the project, the environmental impact and the resource efficiency. The current technical route presents a development pattern of "cast-in-place and prefabricated coexist, rigidity and ductility complement each other, fixed and detachable interweave", but an integrated solution that takes into account efficient construction, recycling and intelligent monitoring has not yet been formed. Although traditional column pile technologies such as cast-in-place piles and steel pipe piles are widely used, they generally have problems such as long construction period, non-recyclable materials, insufficient connection stiffness, environmental pollution, etc. In recent years, prefabricated pile technology has gradually become a research hotspot due to its advantages such as standardized production, fast construction speed, controllable quality, etc., but further breakthroughs are still needed in material ductility, structure optimization, recyclability and intelligent monitoring.

[0003] Bottleneck analysis of traditional technical system:

[0004] 1. Limitations of cast-in-place piles and steel pipe piles

[0005] Cast-in-place piles: formed by on-site drilling and pouring concrete to form the pile body. Although the bearing capacity is high, the construction period is long, the mud pollution is serious, and it cannot be recycled. The connection between the pile body and the upper steel structure relies on concrete filling, which has problems such as low connection stiffness and long consolidation time. Related technologies can be referred to in patent publication CN103046542A, which discloses "deep foundation pit support steel pipe column and concrete cast-in-place pile simultaneous construction process".

[0006] Steel pipe pile: uses steel pipe as the pile body, which has fast construction speed but high cost, and poor uplift performance. When recycled, the pile body needs to be cut, resulting in material waste, which is difficult to meet the requirements of green construction.

[0007] 2. Challenges of stiff composite piles

[0008] Stiff composite piles enhance the strength of the pile body by inserting steel pipes or steel lattice columns, but the core problem is the insufficient reliability of the connection between the prefabricated pile and the steel structure, and the complex construction process makes it difficult to achieve efficient recycling. Related technologies can be referred to in patent publication CN103422493A, which discloses "a column pile for foundation pit".

[0009] 3. Application bottlenecks of prefabricated piles

[0010] Although precast piles (such as prestressed concrete square piles) are standardized in factory production, the traditional precast piles are not flexible enough and are prone to brittle failure in complex geological conditions. In addition, the mechanical connector design (such as angle steel connection) between pile segments has the risk of stress concentration, affecting long-term stability.

[0011] Existing improvement technology progress and breakthrough points to be broken through

[0012] 1. Recyclable combined column pile technology

[0013] In recent years, recyclable design has become a research focus. For example: through the combination of prestressed square piles and steel lattice columns, static pressure construction is used to achieve rapid installation, and through detachable connecting joints and hydraulic converters, 100% recycling is achieved. The advantage is low carbon and environmental protection, but the radial pressure bearing capacity of the lattice column depends on the casing pile driver, and the construction complexity is higher.

[0014] 2. Innovative connection of precast piles and steel structures

[0015] A, flange and bolt connection: through pre-buried end plates and flanges to realize modular connection of precast piles and steel columns, but the reliability of welding or bolt fixation is greatly affected by construction accuracy.

[0016] B, steel pipe reinforced connection technology: a steel pipe is added between the lattice column and the cast-in-place pile to improve the connection stability through anti-slide short reinforcement and end steel plate, such as patent publication No. CN108360746A "a column pile structure and its construction method", but the construction of bored piles still depends on site pouring, and the efficiency is limited.

[0017] 3. Attempt to convert temporary structure to permanent structure

[0018] Inner support lattice column reuse technology: the inner support lattice column of the foundation pit is converted into a permanent structure column by wrapping with concrete, reducing material waste, such as patent publication No. CN104895092A "a method for using an inner support temporary lattice column as a permanent structure column". However, the bonding strength of the lattice column and the concrete depends on additional components such as dowels, and long-term durability needs to be further verified.

[0019] In summary, the existing column piles for deep foundation pit support still have many shortcomings in construction efficiency, pile strength and toughness, and node connection strength, recycling and recycling, etc. Therefore, it is necessary to develop and design a set of column piles with high economic efficiency and high strength and high toughness. SUMMARY

[0020] 1. Technical problems to be solved by the invention

[0021] The present application aims to overcome the above-mentioned deficiencies of the existing column pile, and provide an assembled high-strength toughness composite prefabricated column pile. The technical scheme of the present application is that the foundation pile section located in the foundation pit base stratum and the column section located in the foundation pit are both prefabricated piles, the foundation pile section and the column section are assembled and connected through the bottom plate section, and the column sections are assembled and connected through the support section, so that the column section is easily disassembled and 100% recycled during the foundation pit disassembly stage. Meanwhile, the column section adopts a composite structure of an outer steel structure layer and an inner net rack structure, which greatly reduces the amount of steel used in the previous steel lattice column, improves the economy of the column pile, greatly improves the strength, toughness and tensile strength of the column pile, avoids brittle failure of the column section during construction, and uses a static pressure machine to press or top press, so that the construction process is simpler, the construction efficiency is significantly improved, and the construction depth is not limited in principle, so that the column pile can be used for deeper foundation pit support and has a wider application range. In addition, the bottom plate section and the support section are both pre-buried with upper and lower two-way steel bar connectors, which can improve the connection firmness between the foundation pit bottom plate and the column pile, and between the foundation pit support beam and the column pile, and ensure the stability of the deep foundation pit support.

[0022] 2. Technical scheme

[0023] To achieve the above-mentioned purposes, the technical scheme provided by the present application is as follows:

[0024] The assembled high-strength toughness composite prefabricated column pile of the present application comprises a foundation pile section located in the foundation pit base stratum and a column section located in the foundation pit, the foundation pile section and the column section are both prefabricated piles, the upper end of the foundation pile section is assembled and connected with the lower end of the lowermost column section through a bottom plate section, the bottom plate section is used to connect with the foundation pit bottom plate, the column sections adjacent to each other are assembled and connected through a support section, and the support section is used to connect with the support beam in the foundation pit.

[0025] The column section adopts a structure layer composite structure, which comprises an outer steel structure layer and an inner net rack structure, the inner net rack structure is located inside the outer steel structure layer, and the outer steel structure layer and the inner net rack structure are integrally connected by pouring high-strength concrete.

[0026] The bottom plate section is pre-buried with a bottom plate lower layer steel bar connector and a bottom plate upper layer steel bar connector, the bottom plate lower layer steel bar connector and the bottom plate upper layer steel bar connector are both two-way steel bar connectors, and are used to connect with the steel bar structure in the cast-in-place foundation pit bottom plate in two directions.

[0027] The support section is pre-buried with a support section lower layer steel bar connector and a support section upper layer steel bar connector, the support section lower layer steel bar connector and the support section upper layer steel bar connector are both two-way steel bar connectors, and are used to connect with the steel bar structure in the cast-in-place support beam in two directions.

[0028] Further, the outer steel structure layer of the column section comprises a bottom end cover plate, column section angle steel, a top end cover plate, a bottom end panel, a top end panel and a middle panel, the bottom end cover plate and the top end cover plate are connected into a rectangular frame structure by four column section angle steels, the lower ends of the four column section angle steels are connected by the bottom end panel in sequence, the upper ends are connected by the top end panel in sequence, and a plurality of middle panels are arranged between the four column section angle steels from top to bottom.

[0029] Further, the inner net rack structure of the column section comprises a steel net rack, an outer fiber net rack and an inner fiber net rack, the outer fiber net rack is located outside the steel net rack, the inner fiber net rack is located inside the steel net rack, the steel net rack is connected by main reinforcement and stirrup, and the outer fiber net rack and the inner fiber net rack are both made of FRP high-strength fiber grid.

[0030] Further, polypropylene fiber reinforced material is added to the high-strength concrete in the column section, and the column section is a solid or hollow precast pile structure.

[0031] Further, a foundation pit section monitoring sensor and a wireless communication module are further arranged in the column section, and the foundation pit section monitoring sensor is in communication connection with the background monitoring system through the wireless communication module.

[0032] Further, the bottom plate section comprises a rectangular steel rack and concrete filled in the rectangular steel rack, the rectangular steel rack comprises a bottom end plate, a bottom plate section angle steel, a top end plate and a bottom plate section panel, the bottom end plate and the top end plate are fixedly connected by four bottom plate section angle steels, and the four bottom plate section angle steels are connected by the bottom plate section panel in sequence; the upper and lower ends of the four bottom plate section angle steels are further respectively provided with bottom plate section connecting plates for connecting the foundation pile section and the column section.

[0033] Further, an inner side water stop plate is further embedded in the inner side of the bottom plate section, and an outer side water stop plate and a plurality of studs are further welded on the outer side of the bottom plate section after the foundation pit is excavated.

[0034] Further, the support section comprises a support steel rack and concrete filled in the support steel rack, and a pneumatic fragmentation device is further embedded in the support section, the pneumatic fragmentation device has an outer guide pipe and a cover detachably mounted at the end of the outer guide pipe, and the outer guide pipe is respectively provided with a liquid carbon dioxide filling channel, a positive electrode connecting pipe and a negative electrode connecting pipe.

[0035] Further, the support steel frame of the support section comprises a lower end plate, support section angle steels, an upper end plate and support section patch plates, the lower end plate and the upper end plate are fixedly connected through four support section angle steels, and the four support section angle steels are sequentially connected through support section patch plates; the upper and lower ends of the four support section angle steels are further respectively provided with support section connecting plates for connecting the column sections.

[0036] Further, the foundation pile section is one of a prefabricated solid square pile, a prefabricated hollow square pile, a prestressed prefabricated solid square pile and a prestressed prefabricated hollow square pile; a bottom plate and a bottom end connecting angle steel are arranged at the lower end pile head position of the foundation pile section, and a bottom plate patch plate is further arranged between adjacent bottom end connecting angle steels; a top plate and a top end connecting angle steel are arranged at the upper end pile head position of the foundation pile section, and a top plate patch plate is further arranged between adjacent top end connecting angle steels.

[0037] 3. Beneficial effects

[0038] Compared with the prior art, the technical scheme provided by the present application has the following remarkable effects:

[0039] (1) The prefabricated high-strength and ductile composite column pile of the present application comprises a foundation pile section in the foundation pit bottom stratum and a column section in the foundation pit, and the foundation pile section and the column section are both prefabricated piles, which can be produced in a factory in a standardized manner, thereby shortening the on-site construction period; the upper end of the foundation pile section is connected to the lower end of the lowermost column section through a bottom plate section, and the column sections adjacent in the upper and lower directions are connected through support sections, thereby achieving easy disassembly and 100% recycling of the column sections during the disassembly stage of the foundation pit; the bottom plate section is used to connect to the foundation pit bottom plate, and the support section is used to connect to the support beam in the foundation pit, and the bottom plate section and the support section are both pre-buried with upper and lower layer bidirectional steel reinforcement connectors, which can improve the connection firmness between the foundation pit bottom plate and the column pile and between the foundation pit support beam and the column pile, thereby ensuring the stability of the deep foundation pit support; at the same time, the column section adopts a composite structure of an outer steel structure layer and an inner net rack structure, which on the one hand greatly reduces the steel consumption of the previous steel lattice column, thereby improving the economy of the column pile, and on the other hand greatly improves the strength, ductility and tensile strength of the column pile, which not only avoids brittle failure of the column section during construction, but also allows the column section to be pressed by a static pressure machine, thereby making the construction process simpler and significantly improving the construction efficiency, and the construction depth is not limited in principle, which can be used for deep foundation pit support and has a wider application range.

[0040] (2) The assembled high-strength toughness composite prefabricated column pile of the application, the outer steel structure layer of the column section includes a bottom end cover plate, column section angle steel, a top end cover plate, a bottom end filler plate, a top end filler plate and a middle filler plate, the bottom end cover plate and the top end cover plate are connected into a rectangular frame structure through four column section angle steels, the lower ends of the four column section angle steels are connected through the bottom end filler plate in sequence, the upper ends are connected through the top end filler plate in sequence, and a plurality of middle filler plates are sequentially arranged between the four column section angle steels from top to bottom; compared with the traditional steel lattice column, the column section is integrally connected by pouring the outer steel structure layer and the inner net rack structure by using high-strength concrete, so that the steel consumption of the outer steel structure layer can be reduced, and the steel material use cost of the column section is reduced.

[0041] (3) The assembled high-strength toughness composite prefabricated column pile of the application, the inner net rack structure of the column section includes a steel net rack, an outer fiber net rack and an inner fiber net rack, the outer fiber net rack is located outside the steel net rack, the inner fiber net rack is located inside the steel net rack, the steel net rack is connected by main reinforcement and stirrup, the outer fiber net rack and the inner fiber net rack are both made of FRP high-strength fiber grid, the strength and toughness of the column section can be further improved by using the inner and outer fiber net racks, and the column section is composed of four structure layers from inside to outside, so that the overall steel consumption can be reduced, the manufacturing cost is reduced under the condition of improving the structural strength, toughness and tensile strength of the column pile, and the column pile has the properties of compression resistance, bending resistance and impact resistance.

[0042] (4) The assembled high-strength toughness composite prefabricated column pile of the application, the high-strength concrete in the column section is added with polypropylene fiber reinforced material, which can improve the crack resistance and impact resistance of the concrete, increase the toughness of the concrete, prolong the service life of the column section, and meet the requirement of repeated recycling of the column section.

[0043] (5) The assembled high-strength toughness composite prefabricated column pile of the application, the column section is further provided with a foundation pit section monitoring sensor and a wireless communication module, the foundation pit section monitoring sensor is in communication connection with a background monitoring system through the wireless communication module, data support is provided for intelligent construction, and the intelligent control of foundation pit deformation is facilitated.

[0044] (6) The assembled high-strength toughness composite prefabricated column pile of the application, the bottom plate section includes a rectangular steel rack and concrete filled in the rectangular steel rack, the rectangular steel rack includes a bottom end plate, a bottom plate section angle steel, a top end plate and a bottom plate section filler plate, and the structural strength of the bottom plate section is ensured; meanwhile, an inner water stop plate is pre-buried in the inner side of the bottom plate section, and an outer water stop plate and a plurality of studs are secondarily welded on the outer side of the bottom plate section after the foundation pit is excavated, so that the water stop problem of the column pile and the bottom plate and the connection reliability problem of the column pile and the bottom plate are solved, and the foundation pile section forms an effective supporting effect on the bottom plate.

[0045] (7) The assembled high-strength toughness composite prefabricated column pile of the application, the support section comprises a support steel frame and concrete filled in the support steel frame, a pneumatic fragmentation device is pre-embedded in the support section, and the support section can be effectively and conveniently broken and removed in the dismantling stage, so that the support beam is simple and convenient to remove, and the steel structure of the support section can still be recycled for the second time.

[0046] (8) The assembled high-strength toughness composite prefabricated column pile of the application, the foundation pile section is one of a prefabricated solid square pile, a prefabricated hollow square pile, a prestressed prefabricated solid square pile and a prestressed prefabricated hollow square pile, end plates and connecting angle steels are arranged at the upper and lower pile head positions of the foundation pile section, and a patch plate is additionally arranged, so that the connection reliability of the foundation pile section and the upper column section is ensured. BRIEF DESCRIPTION OF DRAWINGS

[0047] Figure 1 It is a perspective structural schematic view of the assembled high-strength toughness composite prefabricated column pile of the application;

[0048] Figure 2 It is a front view structural schematic view of the assembled high-strength toughness composite prefabricated column pile of the application;

[0049] Figure 3 It is a perspective structural schematic view of the solid column section in the application;

[0050] Figure 4 It is a sectional structural schematic view of the solid column section in the application; Figure 3

[0051] Figure 5 It is a perspective structural schematic view of the hollow column section in the application;

[0052] Figure 6 It is a sectional structural schematic view of the hollow column section in the application; Figure 5

[0053] Figure 7 It is a perspective structural schematic view of the bottom plate section in the application;

[0054] Figure 8 It is a perspective structural schematic view of the support section in the application;

[0055] Figure 9 It is a local enlarged structural schematic view of K in the application; Figure 8

[0056] It is an internal sectional structural schematic view of the external guide pipe in the application; Figure 10 Figure 9 It is a perspective structural schematic view of the solid foundation pile section in the application;

[0057] Figure 11 It is a perspective structural schematic view of the solid foundation pile section in the application;​​​

[0058] Figure 12 Fig. 1 is a perspective view of a hollow foundation pile segment according to the present application.

[0059] Reference numerals in the drawing:

[0060] 1, foundation pile segment; 1-1, bottom plate; 1-2, bottom end connecting angle steel; 1-3, top plate; 1-4, top end connecting angle steel; 1-5, steel reinforcement cage; 1-6, concrete; 1-7, bottom plate patch plate; 1-8, top plate patch plate;

[0061] 2, bottom plate segment; 2-1, bottom end plate; 2-2, bottom plate segment angle steel; 2-3, top end plate; 2-4, bottom plate segment patch plate; 2-5, inner side water stop plate; 2-6, bottom plate lower layer steel reinforcement adapter; 2-7, bottom plate upper layer steel reinforcement adapter; 2-8, bottom plate segment connecting plate; 2-9, outer side water stop plate; 2-10, stud;

[0062] 3, column segment; 3-1, bottom end cover plate; 3-2, column segment angle steel; 3-3, top end cover plate; 3-4, bottom end patch plate; 3-5, top end patch plate; 3-6, middle patch plate; 3-7, steel reinforcement net rack; 3-8, outer layer fiber net rack; 3-9, inner layer fiber net rack; 3-10, high-strength concrete;

[0063] 4, support segment; 4-1, lower end plate; 4-2, support segment angle steel; 4-3, upper end plate; 4-4, support segment patch plate; 4-5, support segment lower layer steel reinforcement adapter; 4-6, support segment upper layer steel reinforcement adapter; 4-7, support segment connecting plate; 4-8, pneumatic fragmentation device; 4-8-1, outer guide pipe; 4-8-1a, liquid carbon dioxide filling channel; 4-8-1b, positive electrode connecting pipe; 4-8-1c, negative electrode connecting pipe; 4-8-2, cover. DETAILED DESCRIPTION

[0064] For a further understanding of the present application, reference will be made to the following detailed description of the application taken in conjunction with the accompanying drawings.

[0065] [EXAMPLE]

[0066] In conjunction with Figure 1 and Figure 2As shown, the prefabricated high-strength and toughness composite prefabricated column pile of the embodiment includes a foundation pile section 1 located in the foundation pit bottom stratum and a column section 3 located in the foundation pit. The foundation pile section 1 and the column section 3 are both prefabricated piles. The upper end of the foundation pile section 1 is connected with the lower end of the lowermost column section 3 through a bottom plate section 2, which is used to be connected with the foundation pit bottom plate. The upper and lower adjacent column sections 3 are connected through a support section 4, which is used to be connected with the support beam in the foundation pit. The bottom plate section 2 and the support section 4 are also prefabricated parts, which can be standardized produced in the factory, shortening the on-site construction period. During construction, the various components of the prefabricated high-strength and toughness composite prefabricated column pile can be assembled in the factory and transported to the construction site by vehicles. Then the foundation pile section 1, the bottom plate section 2, the column section 3 and the support section 4 are pressed into the soil body in turn until the designed elevation is reached. At this time, the foundation pile section 1 is located below the foundation pit bottom stratum, and the bottom plate section 2 is located in the foundation pit bottom. Then the foundation pit soil body is excavated layer by layer. The support beam is constructed in each layer to support the foundation pit. The support beam is connected to the support section 4. The soil body is excavated to the bottom and the bottom plate is constructed. The bottom plate is connected with the bottom plate section 2. During the demolition stage, the column section 3 and the support beam and other structures are removed in turn. The foundation pile section 1 and the bottom plate section 2 remain in the foundation pit stratum. The column section 3 is easily disassembled and 100% recycled during the demolition stage of the foundation pit.

[0067] As shown, Figures 3 to 6 In the embodiment, the column section 3 adopts a composite structure of structural layers, including an outer steel structure layer and an inner net rack structure. The inner net rack structure is located inside the outer steel structure layer and is integrally connected with the outer steel structure layer by high-strength concrete 3-10. Compared with the existing column pile lattice column, the steel lattice column itself cannot withstand high pressure extrusion due to the limitation of its own structure. Especially in the case of static pressure pile pressure or top pressure, the steel lattice column is easily damaged under pressure. In order to prevent brittle failure of the lattice column, the lattice column often needs to be made by thick steel plate and angle steel welding. The steel consumption of the lattice column is large and the compression and bending resistance is limited. The column section 3 with the composite structure in the embodiment is integrally connected by the outer steel structure layer and the inner net rack structure through the high-strength concrete 3-10. The inner net rack structure and the high-strength concrete 3-10 enhance the strength of the outer steel structure layer. At the same time, the column section 3 as a whole plays a role in compression resistance, bending resistance and impact resistance. On the one hand, it greatly reduces the steel consumption of the steel lattice column in the past, improving the economy of the column pile. On the other hand, it greatly improves the strength and toughness and tensile strength of the column pile. It not only avoids brittle failure of the column section during construction, but also has compression resistance, bending resistance and impact resistance. It can use the static pressure machine to press or top pressure. The construction process is simpler and the construction efficiency is significantly improved. Compared with the method of sending pile by steel sleeve for lattice column, the construction depth is not limited in principle. It can be used for deeper foundation pit support and has a wider range of applications.

[0068] In this embodiment, the bottom slab section 2 is used to connect with the foundation pit bottom slab, and the support section 4 is used to connect with the support beams inside the foundation pit. Since the bottom slab and support beams are constructed using a cast-in-place process, both the bottom slab section 2 and the support section 4 are pre-embedded with bidirectional steel reinforcement connectors, which improves the connection strength between the foundation pit bottom slab and the column piles, as well as between the foundation pit support beams and the column piles, ensuring the stability of the deep foundation pit support. Specifically, as... Figure 7 As shown, the bottom slab section 2 is pre-embedded with a lower layer rebar connector 2-6 and a higher layer rebar connector 2-7. Both the lower layer rebar connector 2-6 and the higher layer rebar connector 2-7 are bidirectional rebar connectors, used to connect to the rebar structure in the cast-in-place foundation pit bottom slab in two directions. Figure 8 As shown, the support section 4 is pre-embedded with a lower layer rebar connector 4-5 and an upper layer rebar connector 4-6. Both the lower layer rebar connector 4-5 and the upper layer rebar connector 4-6 are bidirectional rebar connectors, used to connect to the rebar structure in the cast-in-place support beam in two directions. The aforementioned bidirectional rebar connectors can all be vertically pre-embedded steel pipes, used to form insertion holes on the bottom slab section 2 and the support section 4, facilitating the insertion and fixing of the cast-in-place rebar.

[0069] catch Figures 3 to 6 As shown, the prefabricated high-strength and tough composite precast column pile of this embodiment has an outer steel structure layer of column section 3 including a bottom cover plate 3-1, column section angle steel 3-2, top cover plate 3-3, bottom gusset plate 3-4, top gusset plate 3-5 and middle gusset plate 3-6. The bottom cover plate 3-1 and the top cover plate 3-3 are connected to form a rectangular frame structure by four column section angle steels 3-2. The lower ends of the four column section angle steels 3-2 are connected in sequence by the bottom gusset plate 3-4, and the upper ends are connected in sequence by the top gusset plate 3-5. Several middle gusset plates 3-6 are also arranged in sequence from top to bottom between the four column section angle steels 3-2. The structure of the outer steel structure layer is similar to that of existing lattice columns. The difference is that the column section 3 uses high-strength concrete 3-10 to cast and connect the outer steel structure layer and the inner grid structure into one piece. The size and thickness of the bottom cover plate 3-1, column section angle steel 3-2, top cover plate 3-3, bottom gusset plate 3-4, top gusset plate 3-5 and middle gusset plate 3-6 can be designed to be smaller, and the gusset plate spacing can be designed to be larger, reducing the amount of steel used and lowering the steel cost of the column section.

[0070] The inner side net rack structure of the column section 3 comprises a steel bar net rack 3-7, an outer layer fiber net rack 3-8 and an inner layer fiber net rack 3-9. The outer layer fiber net rack 3-8 is located outside the steel bar net rack 3-7, and the inner layer fiber net rack 3-9 is located inside the steel bar net rack 3-7. The steel bar net rack 3-7 is connected by main reinforcement and stirrup. The outer layer fiber net rack 3-8 and the inner layer fiber net rack 3-9 are both made of FRP high-strength fiber grid. The inner and outer fiber net racks can further improve the strength and toughness of the column section 3. The column section 3 is composed of four structure layers from inside to outside (in order: inner layer fiber net rack 3-9, steel bar net rack 3-7, outer layer fiber net rack 3-8 and outer side steel structure layer), which can reduce the overall steel consumption. In the case of improving the strength, toughness and tensile strength of the column pile structure, the manufacturing cost is reduced, and the column pile has the properties of compression resistance, bending resistance and impact resistance. In this embodiment, polypropylene fiber reinforced material is added to the high-strength concrete 3-10 of the column section 3, which can improve the crack resistance and impact resistance of the concrete, increase the toughness of the concrete, prolong the service life of the column section 3, and meet the requirements of repeated recycling of the column section 3. In this embodiment, the column section 3 is a solid or hollow prefabricated pile structure, Figure 3 and Figure 4 The structure of the solid column section is shown in the structural schematic diagram, Figure 5 and Figure 6 The structure of the hollow column section is shown in the structural schematic diagram.

[0071] In addition, in this embodiment, the column section 3 also has a foundation pit section monitoring sensor and a wireless communication module built-in. The foundation pit section monitoring sensor is in communication connection with the background monitoring system through the wireless communication module, providing data support for intelligent construction, which is beneficial to intelligent control of foundation pit deformation. The foundation pit section monitoring sensor comprises a stress monitor, a displacement monitor and an axial force detector and the like. Since the column section 3 can be 100% recycled, the foundation pit section monitoring sensor and the wireless communication module in the column section 3 can be reused, reducing the sensor reuse and maintenance cost.

[0072] Referring to Figure 7As shown, in the present embodiment, the bottom plate section 2 comprises a rectangular steel frame and concrete filled in the rectangular steel frame, the rectangular steel frame comprises a bottom end plate 2-1, a bottom plate section angle steel 2-2, a top end plate 2-3 and a bottom plate section patch plate 2-4, the bottom end plate 2-1 and the top end plate 2-3 are fixedly connected through four bottom plate section angle steels 2-2, and the four bottom plate section angle steels 2-2 are sequentially connected through the bottom plate section patch plates 2-4. The bottom end plate 2-1, the bottom plate section angle steel 2-2, the top end plate 2-3 and the bottom plate section patch plate 2-4 are all connected and fixed by welding process. The upper and lower ends of the four bottom plate section angle steels 2-2 are respectively provided with bottom plate section connecting plates 2-8 for connecting the foundation pile section 1 and the column section 3, the bottom plate section connecting plates 2-8 can adopt an angle steel structure, which can be connected with the bottom plate section angle steel 2-2 and the angle steels at the four corners of the foundation pile section 1 and the column section 3 through flat head bolts, facilitating quick disassembly of the column section 3. In addition, the inner side of the bottom plate section 2 is also pre-buried with an inner side water stop plate 2-5, and the outer side of the bottom plate section 2 is also welded with an outer side water stop plate 2-9 and a plurality of pegs 2-10 after the foundation pit is excavated. The inner side water stop plate 2-5 is pre-provided in the bottom plate section 2, and the bottom plate section 2 is subjected to secondary welding construction before the construction of the foundation pit bottom plate, that is, the outer side water stop plate 2-9 and the pegs 2-10 are welded and fixed on the outer side of the bottom plate section 2, and the outer side water stop plate 2-9 and the pegs 2-10 can be welded on the bottom plate section angle steel 2-2, solving the water stop problem of the column pile and the bottom plate and the connection reliability problem of the column pile and the bottom plate, and utilizing the foundation pile section 1 to form effective supporting effect on the bottom plate.

[0073] Referring to Figures 8 to 10As shown, in the embodiment, the support section 4 comprises a support steel frame and concrete filled in the support steel frame. Since the support section 4 and the support beam are formed into a support joint by cast-in-situ, considering the difficulty of removing the support beam after cast-in-situ, a pneumatic fragmentation device 4-8 is pre-embedded in the support section 4, which can effectively and conveniently break and remove the support section 4 in the demolition stage, so that the support beam is simple and convenient to remove, and the steel structure of the support section 4 can still be recycled for the second time. Specifically, the pneumatic fragmentation device 4-8 adopts the principle of gas blasting, and the pneumatic fragmentation device 4-8 has an outer lead pipe 4-8-1 and a cover 4-8-2 detachably installed at the end of the outer lead pipe 4-8-1, and the outer lead pipe 4-8-1 is respectively provided with a liquid carbon dioxide filling channel 4-8-1a, a positive electrode connecting pipe 4-8-1b and a negative electrode connecting pipe 4-8-1c. In the pressing process, the outer lead pipe 4-8-1 is blocked by the cover 4-8-2 to prevent dirt such as soil from entering the outer lead pipe 4-8-1; when pouring the support beam, according to the position of the support beam, the outer lead pipe 4-8-1 can be connected with an external hose, and the other end of the external hose extends outside the support beam, which is convenient for subsequent breaking operation; when demolishing, liquid carbon dioxide is injected into the pneumatic fragmentation device 4-8 through the liquid carbon dioxide filling channel 4-8-1a, the power supply is connected through the positive electrode connecting pipe 4-8-1b and the negative electrode connecting pipe 4-8-1c, and the liquid carbon dioxide is converted into high-pressure carbon dioxide gas by using electrode heating, so that the concrete of the support section 4 is broken from the inside, which is convenient for the removal of the support beam and the recycling of the support steel frame in the support section 4.

[0074] Interface Figure 8 As shown, in the embodiment, the support steel frame of the support section 4 comprises a lower end plate 4-1, a support section angle steel 4-2, an upper end plate 4-3 and a support section patch plate 4-4, the lower end plate 4-1 and the upper end plate 4-3 are fixedly connected by four support section angle steels 4-2, and the four support section angle steels 4-2 are sequentially connected by the support section patch plates 4-4. The lower end plate 4-1, the support section angle steel 4-2, the upper end plate 4-3 and the support section patch plate 4-4 are connected and fixed by welding process. The upper and lower ends of the four support section angle steels 4-2 are respectively provided with support section connecting plates 4-7 for connecting the column section 3. The support section connecting plate 4-7 can adopt an angle steel structure, which can be connected with the angle steel at the four corners of the column section 3 by means of a flat head bolt, so as to facilitate the quick disassembly of the column section 3. The length of the column section 3 can be determined according to the floor height of the underground floor, and the number of use can be determined according to the depth of the foundation pit or the number of layers of the underground floor, and the upper and lower adjacent column sections 3 can be connected by the support section 4.

[0075] As Figure 11 And Figure 12 As shown, the foundation pile section 1 in the embodiment is one of a prefabricated solid square pile, a prefabricated hollow square pile, a prestressed prefabricated solid square pile and a prestressed prefabricated hollow square pile. Figure 11A solid square pile is shown, Figure 12 A hollow square pile is shown. The foundation pile section 1 is mainly composed of concrete 1-6 and a steel reinforcement cage 1-5 arranged in the concrete 1-6, and different from the existing prefabricated square pile, in order to improve the connection reliability, a bottom plate 1-1 and a bottom end connecting angle steel 1-2 are arranged at the lower end pile head position of the foundation pile section 1, and a bottom plate patch plate 1-7 is further arranged between adjacent bottom end connecting angle steels 1-2; a top plate 1-3 and a top end connecting angle steel 1-4 are arranged at the upper end pile head position of the foundation pile section 1, and a top plate patch plate 1-8 is further arranged between adjacent top end connecting angle steels 1-4. The length and width of the bottom end connecting angle steel 1-2 and the top end connecting angle steel 1-4 are increased, and connecting screw holes can be reserved thereon to facilitate connection with the bottom plate section 2. The patch plates are arranged at the upper and lower pile head positions of the foundation pile section 1, which ensures the connection reliability of the foundation pile section 1 and the upper column section 3.

[0076] In order to further understand the technical scheme of the present application, the construction process of the assembled high-strength and ductile composite prefabricated column pile of the present application will be further described in combination with the above drawings.

[0077] S1, first, design drawings of column piles at various positions are designed through relevant engineering drawings and relevant data;

[0078] S2, the relevant production is carried out according to the column pile design drawings in the prefabrication factory; the corresponding foundation pile section 1, bottom plate section 2, column section 3 and support section 4 are produced;

[0079] S3, the foundation pile section 1, bottom plate section 2, column section 3 and support section 4 are assembled in the assembly factory; and are transported to the site construction site by vehicles;

[0080] S4, the construction of the column pile is carried out by the static pressure machine: first, the construction of the foundation pile section 1 is carried out, and then the construction of the bottom plate section 2, column section 3 and support section 4 which have been assembled in the factory is carried out in turn; finally, the column pile is sent to the designed elevation by the pile sender, and the construction is completed;

[0081] S5, in the demolition stage, first, the secondary construction of the bottom plate section 2 is completed, that is, the construction of the bottom plate section 2 and the foundation pit bottom plate, so that the bottom plate section 2 and the foundation pit bottom plate are connected together; then the column section 3 is removed in turn, and the support section 4 is removed by the pneumatic fragmentation device 4-8;

[0082] S6, according to the next project, the matching design is carried out, and the construction is repeated.

[0083] The assembled high-strength toughness composite prefabricated column pile of the application is characterized in that: the foundation pile section in the foundation pit base stratum and the column section in the foundation pit are both prefabricated piles, the foundation pile section and the column section are assembled and connected through the bottom plate section, and the column sections are assembled and connected through the support sections, so that the column section is easily disassembled and 100% recycled in the foundation pit disassembly stage; meanwhile, the column section adopts the composite structure of the outer steel structure layer and the inner net rack structure, which greatly reduces the steel consumption of the previous steel lattice column, improves the economy of the column pile, greatly improves the strength, toughness and tensile strength of the column pile, avoids the brittle failure of the column section in the construction process, and uses the static pressure machine to press or top pressure, so that the construction process is simpler, the construction efficiency is significantly improved, the construction depth is not limited in principle, and the column pile can be used for deeper foundation pit support, so that the application range is wider; in addition, the bottom plate section and the support section are both pre-buried with the upper and lower two-way steel bar connectors, which can improve the connection firmness between the foundation pit bottom plate and the column pile, and between the foundation pit support beam and the column pile, and ensure the stability of the deep foundation pit support; the support section is also pre-buried with the pneumatic fragmentation device, which can effectively and conveniently break and remove the support section in the disassembly stage, so that the support beam is easily disassembled, and the steel structure of the support section can be recycled again.

[0084] The above describes the application and its embodiments in a schematic manner, which is not limited, and the drawings only show one of the embodiments of the application, and the actual structure is not limited thereto. Therefore, if a person skilled in the art is inspired by it, without departing from the purpose of the application, similar structural modes and embodiments can be designed without creativity, which should all belong to the protection scope of the application.

Claims

1. A prefabricated high-strength and ductile composite precast column pile, comprising a foundation pile section (1) located in the stratum of the foundation pit bottom and a column section (3) located in the foundation pit, the foundation pile section (1) and the column section (3) are both precast piles, characterized in that: The upper end of the foundation pile section (1) is assembled and connected with the lower end of the lowermost column section (3) through a bottom plate section (2), the bottom plate section (2) is used for being connected with a foundation pit bottom plate; the column sections (3) adjacent in upper and lower directions are assembled and connected through support sections (4), the support sections (4) are used for being connected with support beams in the foundation pit; wherein, The column section (3) adopts a structural layer composite structure, comprising an outer steel structure layer and an inner net rack structure, the inner net rack structure is located at the inner side of the outer steel structure layer, and the outer steel structure layer and the inner net rack structure are integrally poured and connected through high-strength concrete (3-10); The bottom plate section (2) is pre-buried with a bottom plate lower layer steel bar connector (2-6) and a bottom plate upper layer steel bar connector (2-7), the bottom plate lower layer steel bar connector (2-6) and the bottom plate upper layer steel bar connector (2-7) are both bidirectional steel bar connectors, used for being connected with a steel bar structure in a cast-in-place foundation pit bottom plate in two directions; the bottom plate section (2) comprises a rectangular steel frame and concrete filled in the rectangular steel frame, the rectangular steel frame comprises a bottom end plate (2-1), a bottom plate section angle steel (2-2), a top end plate (2-3) and a bottom plate section patch plate (2-4), the bottom end plate (2-1) and the top end plate (2-3) are fixedly connected through four bottom plate section angle steels (2-2), and the four bottom plate section angle steels (2-2) are sequentially connected through bottom plate section patch plates (2-4); the upper and lower ends of the four bottom plate section angle steels (2-2) are further respectively provided with bottom plate section connecting plates (2-8) for connecting the foundation pile section (1) and the column section (3); the inner side of the bottom plate section (2) is further pre-buried with an inner side water stop plate (2-5), and the outer side of the bottom plate section (2) is further welded with an outer side water stop plate (2-9) and a plurality of pegs (2-10) after the foundation pit is excavated; The support section (4) is pre-buried with a support section lower layer steel bar connector (4-5) and a support section upper layer steel bar connector (4-6), both of which are two-way steel bar connectors, used to be connected with the steel bar structure in the cast-in-place support beam in two directions; the support section (4) comprises a support steel frame and concrete filled in the support steel frame, and a pneumatic fragmentation device (4-8) is further pre-buried in the support section (4), the pneumatic fragmentation device (4-8) has an outer guide pipe (4-8-1) and a cover (4-8-2) detachably mounted at the end of the outer guide pipe (4-8-1), and the outer guide pipe (4-8-1) is respectively provided with a liquid carbon dioxide filling channel (4-8-1a), a positive electrode connecting pipe (4-8-1b) and a negative electrode connecting pipe (4-8-1c); the support steel frame of the support section (4) comprises a lower end plate (4-1), a support section angle steel (4-2), an upper end plate (4-3) and a support section patch plate (4-4), the lower end plate (4-1) and the upper end plate (4-3) are fixedly connected through four support section angle steels (4-2), and the four support section angle steels (4-2) are sequentially connected through support section patch plates (4-4); the upper and lower ends of the four support section angle steels (4-2) are further respectively provided with support section connecting plates (4-7) for connecting the column section (3).

2. The fabricated high-strength tough composite precast column pile according to claim 1, characterized in that: The outer side steel structure layer of the column section (3) comprises a bottom end cover plate (3-1), a column section angle steel (3-2), a top end cover plate (3-3), a bottom end patch plate (3-4), a top end patch plate (3-5) and a middle patch plate (3-6), the bottom end cover plate (3-1) and the top end cover plate (3-3) are connected into a rectangular frame structure through four column section angle steels (3-2), the lower ends of the four column section angle steels (3-2) are sequentially connected through the bottom end patch plate (3-4), the upper ends are sequentially connected through the top end patch plate (3-5), and a plurality of middle patch plates (3-6) are further sequentially arranged between the four column section angle steels (3-2) from top to bottom.

3. The fabricated high-strength toughness composite precast column pile according to claim 1 or 2, characterized in that: The inner side net rack structure of the column section (3) comprises a steel bar net rack (3-7), an outer layer fiber net rack (3-8) and an inner layer fiber net rack (3-9), the outer layer fiber net rack (3-8) is located on the outer side of the steel bar net rack (3-7), and the inner layer fiber net rack (3-9) is located on the inner side of the steel bar net rack (3-7), the steel bar net rack (3-7) is connected by main reinforcement and stirrup, and the outer layer fiber net rack (3-8) and the inner layer fiber net rack (3-9) are both made of FRP high-strength fiber grid.

4. The fabricated high-strength tough composite precast column pile according to claim 3, characterized in that: The high-strength concrete (3-10) of the column section (3) is added with polypropylene fiber reinforced material, and the column section (3) is a solid or hollow precast pile structure.

5. The fabricated high-strength ductile composite precast column pile according to claim 1, wherein: The column section (3) is further provided with a foundation pit section monitoring sensor and a wireless communication module, and the foundation pit section monitoring sensor is in communication connection with the background monitoring system through the wireless communication module.

6. The fabricated high-strength ductile composite precast column pile according to claim 1, wherein: The base pile section (1) is one of a prefabricated solid square pile, a prefabricated hollow square pile, a prestressed prefabricated solid square pile and a prestressed prefabricated hollow square pile; a bottom plate (1-1) and a bottom end connecting angle steel (1-2) are arranged at a lower end pile head position of the base pile section (1), and a bottom plate patch plate (1-7) is further arranged between adjacent bottom end connecting angle steels (1-2); a top plate (1-3) and a top end connecting angle steel (1-4) are arranged at an upper end pile head position of the base pile section (1), and a top plate patch plate (1-8) is further arranged between adjacent top end connecting angle steels (1-4).

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