Fabricated high-strength and high-toughness composite prefabricated stand column pile

Abstract

The invention discloses an assembly type high-strength toughness composite prefabricated stand column pile, and belongs to the technical field of foundation pit supporting. The assembly type high-strength toughness composite prefabricated stand column pile comprises the foundation pile section and the stand column sections, the foundation pile section and the stand column sections are assembled and connected through the bottom plate section, the stand column sections are assembled and connected through the supporting sections, and easy disassembly and 100% recycling of the stand column sections in the foundation pit support disassembly stage are achieved; meanwhile, the stand column section is of a structural layer composite structure, on one hand, the steel consumption of an existing steel latticed column is greatly reduced, on the other hand, the strength, toughness and tensile strength of the stand column pile are greatly improved, holding pressing or jacking pressing can be achieved through a static press, the construction process is simpler, the construction efficiency is remarkably improved, and the application range is wider; in addition, the upper-layer and lower-layer two-way steel bar connectors are embedded in the bottom plate section and the supporting section, 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 can be improved, and the stability of deep foundation pit supporting is guaranteed.

Description

Technical Field

[0001] The invention relates to a column pile for deep foundation pit support, and more specifically to an assembled high-strength and toughness composite prefabricated column pile. Background Art

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

[0003] Bottleneck analysis of traditional technology system:

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

[0005] Cast-in-place piles: The pile body is formed by drilling holes on site and pouring concrete. 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 depends on concrete filling, which has problems such as low connection stiffness and long consolidation time. For related technologies, please refer to the "Simultaneous construction process of supporting steel pipe columns and concrete cast-in-place piles in deep foundation pits" disclosed in patent publication number CN103046542A.

[0006] Steel pipe piles: Using steel pipes as pile bodies, the construction speed is fast but the cost is high, and the pull-out resistance is poor. The pile body needs to be cut during recycling, resulting in material waste, which makes it difficult to meet the requirements of green construction.

[0007] 2. Challenges of rigid composite piles

[0008] The strength of the rigid composite pile is enhanced by inserting steel pipes or steel lattice columns, but the core problem is that the connection reliability between the prefabricated pile and the steel structure is insufficient, and the construction process is complicated, making it difficult to achieve efficient recycling. For related technologies, please refer to the "A column pile for foundation pit" disclosed in patent publication number CN103422493A.

[0009] 3. Application bottleneck of precast piles

[0010] Although precast piles (such as prestressed concrete square piles) are standardized in factories, they are not tough enough and are prone to brittle failure under complex geological conditions. In addition, the design of mechanical connectors between pile segments (such as angle steel connections) poses a risk of stress concentration, affecting long-term stability.

[0011] Existing technological progress and potential breakthroughs

[0012] 1. Recyclable combined column pile technology

[0013] In recent years, recyclable design has become a research focus. For example, by combining prestressed square piles with steel lattice columns, static pressure construction is used to achieve rapid installation, and 100% recycling is achieved through detachable connection joints and hydraulic converters. Its 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 relatively high.

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

[0015] A. Flange and bolt connection: The modular connection between precast piles and steel columns is achieved through embedded end plates and flanges, but the reliability of welding or bolt fixing is greatly affected by the construction accuracy.

[0016] B. Steel pipe reinforced connection technology: Add steel pipes between lattice columns and cast-in-place piles, and improve the connection stability through anti-slip short reinforcement and head steel plates, such as "A column pile structure and its construction method" disclosed in patent publication number CN108360746A. However, the construction of bored piles still relies on on-site casting, which limits efficiency.

[0017] 3. Attempt to transform temporary structure into permanent structure

[0018] Internal support lattice column reuse technology: The foundation pit support lattice column is converted into a permanent structural column by external concrete wrapping to reduce material waste, such as the "A method of using an internal support temporary lattice column as a permanent structural column" disclosed in patent publication number CN104895092A. However, the bonding strength between the lattice column and the concrete depends on additional components such as studs, and the 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 terms of construction efficiency, pile strength and toughness, node connection strength, recycling and reuse, etc. Therefore, it is very necessary to develop and design a set of column piles with high economy, high strength and high toughness. Summary of the invention

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

[0021] The purpose of the present invention is to overcome the above-mentioned shortcomings of the existing column piles and provide an assembled high-strength and toughness composite prefabricated column pile. By adopting the technical solution of the present invention, the foundation pile section located in the bottom stratum of the foundation pit 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 by the bottom plate section, and the column sections are assembled and connected by the support section, so that the column section can be easily disassembled and 100% recycled during the dismantling stage of the foundation pit; at the same time, the column section adopts a composite structure of an outer steel structure layer and an inner grid structure, which greatly reduces the steel consumption of the previous steel lattice column and improves On the one hand, it improves the economy of the column piles, and on the other hand, it greatly improves the strength, toughness and tensile strength of the column piles. It can not only avoid the brittle failure of the column section during construction, but also can use the static press to hold or press, the construction process is simpler, the construction efficiency is significantly improved, and the construction depth is not limited in principle. It can be used for deeper foundation pit support and has a wider range of applications. In addition, the bottom plate section and the support section are pre-embedded with upper and lower bidirectional steel bar connectors, which can improve the connection firmness between the foundation pit bottom plate and the column piles, and between the foundation pit support beam and the column piles, thereby ensuring the stability of the deep foundation pit support.

[0022] 2. Technical solution

[0023] In order to achieve the above object, the technical solution provided by the present invention is:

[0024] The present invention discloses an assembled high-strength and tough composite prefabricated column pile, comprising a foundation pile section located in the bottom stratum of a foundation pit and a column section located in the foundation pit, wherein both the foundation pile section and the column section are prefabricated piles, and the upper end of the foundation pile section is assembled and connected with the lower end of the column section located at the lowest part through a bottom plate section, and the bottom plate section is used to connect with the bottom plate of the foundation pit; the upper and lower adjacent column sections are assembled and connected through a support section, and the support section is used to connect with the support beam in the foundation pit; wherein,

[0025] The column section adopts a structural layer composite structure, including an outer steel structure layer and an inner grid structure, wherein the inner grid structure is located inside the outer steel structure layer, and the outer steel structure layer and the inner grid structure are cast and connected as one by high-strength concrete;

[0026] The bottom plate section is pre-embedded with a bottom plate lower layer steel bar connector and a bottom plate upper layer steel bar connector, and the bottom plate lower layer steel bar connector and the bottom plate upper layer steel bar connector are both bidirectional steel bar connectors, which 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-embedded with a lower layer steel bar connector and an upper layer steel bar connector. Both the lower layer steel bar connector and the upper layer steel bar connector are bidirectional steel bar connectors, which are used to connect to the steel bar structure in the cast-in-place support beam in two directions.

[0028] Furthermore, the outer steel structure layer of the column section includes a bottom cover plate, a column section angle steel, a top cover plate, a bottom gusset plate, a top gusset plate and a middle gusset plate. The bottom cover plate and the top cover plate are connected to form a rectangular frame structure through four column section angle steels. The lower ends of the four column section angle steels are connected in sequence through the bottom gusset plate, and the upper ends are connected in sequence through the top gusset plate. A number of middle gusset plates are also arranged in sequence from top to bottom between the four column section angle steels.

[0029] Furthermore, the inner grid structure of the column section includes a steel grid, an outer fiber grid and an inner fiber grid, the outer fiber grid is located on the outer side of the steel grid, the inner fiber grid is located on the inner side of the steel grid, the steel grid is connected by main bars and stirrups, and the outer fiber grid and the inner fiber grid are both made of FRP high-strength fiber mesh.

[0030] Furthermore, polypropylene fiber reinforcement material is added to the high-strength concrete of the column section, and the column section is a solid or hollow prefabricated pile structure.

[0031] Furthermore, a foundation pit section monitoring sensor and a wireless communication module are also built into the column section, and the foundation pit section monitoring sensor is communicatively connected to the background monitoring system via the wireless communication module.

[0032] Furthermore, the bottom plate section includes a rectangular steel frame and concrete filled in the rectangular steel frame, the rectangular steel frame includes a bottom end plate, a bottom plate section angle steel, a top end plate and a bottom plate section connecting plate, 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 in turn by the bottom plate section connecting plates; the upper and lower ends of the four bottom plate section angle steels are respectively provided with bottom plate section connecting plates for connecting the foundation pile section and the column section.

[0033] Furthermore, an inner water stop plate is pre-buried on the inner side of the bottom plate section, and an outer water stop plate and a plurality of bolts are welded to the outer side of the bottom plate section for a second time after the foundation pit is excavated.

[0034] Furthermore, the support section includes a support steel frame and concrete filled in the support steel frame. A pneumatic fragmentation device is also pre-buried in the support section. The pneumatic fragmentation device has an external lead pipe and a cover detachably installed at the end of the external lead pipe. A liquid carbon dioxide infusion channel, a positive electrode connecting pipe and a negative electrode connecting pipe are respectively provided in the external lead pipe.

[0035] Furthermore, the supporting steel frame of the supporting section includes a lower end plate, a supporting section angle steel, an upper end plate and a supporting section connecting plate. The lower end plate and the upper end plate are fixedly connected by four supporting section angle steels, and the four supporting section angle steels are connected in turn by the supporting section connecting plates; the upper and lower ends of the four supporting section angle steels are respectively provided with supporting section connecting plates for connecting the column sections.

[0036] Furthermore, the foundation pile segment 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 connecting angle steel are provided at the lower pile head position of the foundation pile segment, and a bottom plate connecting plate is also provided between adjacent bottom connecting angle steels; a top plate and a top connecting angle steel are provided at the upper pile head position of the foundation pile segment, and a top plate connecting plate is also provided between adjacent top connecting angle steels.

[0037] 3. Beneficial effects

[0038] Compared with the existing known technologies, the technical solution provided by the present invention has the following significant effects:

[0039] (1) The present invention provides an assembled high-strength and tough composite prefabricated column pile, which includes a foundation pile section located in the bottom stratum of a foundation pit and a column section located in the foundation pit. Both the foundation pile section and the column section are prefabricated piles and can be standardized in a factory to shorten the on-site construction period. The upper end of the foundation pile section is assembled and connected with the lower end of the column section located at the bottom through a bottom plate section, and the upper and lower adjacent column sections are assembled and connected through a support section, thereby achieving easy disassembly and 100% recycling of the column section during the foundation pit support removal stage. The bottom plate section is used to connect to the bottom plate of the foundation pit, and the support section is used to connect to the support beam in the foundation pit, and both the bottom plate section and the support section are pre-embedded with upper and lower layers of bidirectional steel bars for connecting. The device can improve the connection firmness between the foundation pit bottom plate and the column piles, as well as the foundation pit support beam and the column piles, and ensure 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 grid structure, which, on the one hand, greatly reduces the steel consumption of the previous steel lattice column and improves the economy of the column piles; on the other hand, it greatly improves the strength, toughness and tensile strength of the column piles, which can not only avoid the brittle failure of the column section during construction, but also can use a static press to hold or top press, making the construction process simpler, the construction efficiency is significantly improved, and the construction depth is not limited in principle, so it can be used for deeper foundation pit support and has a wider range of applications.

[0040] (2) The present invention provides an assembled high-strength and tough composite prefabricated column pile, wherein the outer steel structure layer of the column section includes a bottom cover plate, a column section angle steel, a top cover plate, a bottom gusset plate, a top gusset plate and a middle gusset plate. The bottom cover plate and the top cover plate are connected to form a rectangular frame structure through four column section angle steels. The lower ends of the four column section angle steels are connected in sequence through the bottom gusset plate, and the upper ends are connected in sequence through the top gusset plate. A number of middle gusset plates are also arranged in sequence from top to bottom between the four column section angle steels. Compared with the traditional steel lattice column, the column section uses high-strength concrete to cast and connect the outer steel structure layer and the inner grid structure into one, so that the amount of steel used in the outer steel structure layer can be less, thereby reducing the steel use cost of the column section.

[0041] (3) The present invention provides an assembled high-strength and toughness composite prefabricated column pile, wherein the inner grid structure of the column section includes a steel grid, an outer fiber grid and an inner fiber grid, wherein the outer fiber grid is located on the outer side of the steel grid, and the inner fiber grid is located on the inner side of the steel grid, wherein the steel grid is formed by connecting main bars and stirrups, and both the outer fiber grid and the inner fiber grid are made of FRP high-strength fiber mesh. The use of the inner and outer fiber grids can further improve the strength and toughness of the column section, and the column section is composited from the inside to the outside through four structural layers, which can reduce the overall steel consumption. While improving the structural strength, toughness and tensile strength of the column pile, the production cost is reduced, so that the column pile has both compression resistance, bending resistance and impact resistance.

[0042] (4) The present invention provides an assembled high-strength and tough composite prefabricated column pile, in which the high-strength concrete of the column section is added with polypropylene fiber reinforcement material, which can improve the anti-cracking and anti-abrasion properties of the concrete, increase the toughness of the concrete, and increase the service life of the column section, thus meeting the requirements for repeated recycling of the column section.

[0043] (5) The present invention provides an assembled high-strength and tough composite prefabricated column pile, in which a foundation pit section monitoring sensor and a wireless communication module are built into the column section. The foundation pit section monitoring sensor is connected to the background monitoring system through the wireless communication module to provide data support for intelligent construction, which is conducive to intelligent control of foundation pit deformation.

[0044] (6) The present invention provides an assembled high-strength and tough composite prefabricated column pile, wherein the bottom plate section includes a rectangular steel frame and concrete filled in the rectangular steel frame, wherein the rectangular steel frame includes a bottom end plate, a bottom plate section angle steel, a top end plate and a bottom plate section gusset plate, thereby ensuring the structural strength of the bottom plate section; at the same time, an inner water stop plate is pre-buried on the inner side of the bottom plate section, and an outer water stop plate and a plurality of bolts are welded to the outer side of the bottom plate section for a second time after excavation of the foundation pit, thereby solving the water stop problem between the column pile and the bottom plate and the connection reliability problem between the column pile and the bottom plate, and utilizing the foundation pile section to form an effective support for the bottom plate.

[0045] (7) The present invention provides an assembled high-strength and tough composite prefabricated column pile, wherein the support section includes a support steel frame and concrete filled in the support steel frame. A pneumatic crushing device is also embedded in the support section, which can effectively and conveniently break and remove the support section during the support removal stage, making the removal of the support beam simple and convenient. At the same time, the steel structure of the support section can still be recycled for a second time.

[0046] (8) The present invention provides an assembled high-strength and toughness composite prefabricated column pile, wherein 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. The upper and lower pile heads of the foundation pile section are provided with end plates and connecting angle steels, and additional gusset plates are added to ensure the connection reliability between the foundation pile section and the upper column section. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 It is a schematic diagram of the three-dimensional structure of an assembled high-strength and toughness composite prefabricated column pile of the present invention;

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

[0049] Figure 3 It is a perspective structural schematic diagram of a solid column section in the present invention;

[0050] Figure 4 for Figure 3 A schematic diagram of the cross-sectional structure of a solid column section;

[0051] Figure 5 It is a perspective structural schematic diagram of the hollow column section in the present invention;

[0052] Figure 6 for Figure 5 A schematic diagram of the cross-sectional structure of the hollow column section;

[0053] Figure 7 It is a perspective structural schematic diagram of the bottom plate section of the present invention;

[0054] Figure 8 It is a perspective structural schematic diagram of the support section in the present invention;

[0055] Fig. 9 for Figure 8 Schematic diagram of the local enlarged structure at K in the middle;

[0056] Fig.10 for Fig. 9 Schematic diagram of the internal cross-sectional structure of the middle and outer guide tubes;

[0057] Fig.11 It is a perspective structural schematic diagram of a solid foundation pile section in the present invention;

[0058] Fig.12 It is a perspective structural schematic diagram of the hollow foundation pile section in the present invention.

[0059] Explanation of the symbols in the schematic diagram:

[0060] 1. Foundation pile section; 1-1. Bottom plate; 1-2. Bottom connecting angle steel; 1-3. Top plate; 1-4. Top connecting angle steel; 1-5. Steel cage; 1-6. Concrete; 1-7. Bottom plate gusset plate; 1-8. Top plate gusset plate;

[0061] 2. Bottom plate section; 2-1. Bottom end plate; 2-2. Bottom plate section angle steel; 2-3. Top end plate; 2-4. Bottom plate section gusset plate; 2-5. Inner water stop plate; 2-6. Bottom plate lower layer steel bar connector; 2-7. Bottom plate upper layer steel bar connector; 2-8. Bottom plate section connecting plate; 2-9. Outer water stop plate; 2-10. Studs;

[0062] 3. Column section; 3-1. Bottom cover plate; 3-2. Column section angle steel; 3-3. Top cover plate; 3-4. Bottom gusset plate; 3-5. Top gusset plate; 3-6. Middle gusset plate; 3-7. Steel mesh frame; 3-8. Outer fiber mesh frame; 3-9. Inner fiber mesh frame; 3-10. High-strength concrete;

[0063] 4. Support section; 4-1. Lower end plate; 4-2. Angle steel of support section; 4-3. Upper end plate; 4-4. Support section gusset plate; 4-5. Lower steel bar connector of support section; 4-6. Upper steel bar connector of support section; 4-7. Connecting plate of support section; 4-8. Pneumatic fragmentation device; 4-8-1. External lead pipe; 4-8-1a. Liquid carbon dioxide perfusion channel; 4-8-1b. Positive electrode connecting pipe; 4-8-1c. Negative electrode connecting pipe; 4-8-2. Cover. DETAILED DESCRIPTION

[0064] In order to further understand the content of the present invention, the present invention is described in detail in conjunction with the accompanying drawings and embodiments.

[0065] [Example]

[0066] Combination Figure 1 and Figure 2As shown, an assembled high-strength and toughness composite prefabricated column pile of this embodiment includes a foundation pile segment 1 located in the bottom stratum of the foundation pit and a column segment 3 located in the foundation pit. Both the foundation pile segment 1 and the column segment 3 are prefabricated piles. The upper end of the foundation pile segment 1 and the lower end of the column segment 3 located at the bottom are assembled and connected through a bottom plate segment 2, and the bottom plate segment 2 is used to connect to the bottom plate of the foundation pit; the upper and lower adjacent column segments 3 are assembled and connected through a support segment 4, and the support segment 4 is used to connect to the support beam in the foundation pit. The bottom plate segment 2 and the support segment 4 are also prefabricated parts, which can be standardized in the factory to shorten the on-site construction period. During construction, the various components of the assembled high-strength and toughness composite prefabricated column pile can be assembled in the factory and transported to the construction site by vehicle. The foundation pile segment 1, the bottom plate segment 2, the column segment 3 and the support segment 4 are pressed into the soil in turn until they reach the designed elevation. At this time, the foundation pile segment 1 is located below the foundation pit base stratum, and the bottom plate segment 2 is located at the foundation pit base. Then the foundation pit soil is excavated layer by layer, and each layer is constructed in turn to support the foundation pit. The support beam is connected to the support segment 4 until the soil is excavated to the base, and the base bottom plate is constructed to connect the bottom plate with the bottom plate segment 2. In the dismantling stage, the column segment 3 and the support beam and other structures are dismantled in turn, and the foundation pile segment 1 and the bottom plate segment 2 are retained in the foundation pit stratum, so that the column segment 3 can be easily dismantled and 100% recycled in the foundation pit dismantling stage.

[0067] like Figures 3 to 6 As shown, in this embodiment, the column section 3 adopts a structural layer composite structure, including an outer steel structure layer and an inner grid structure. The inner grid structure is located on the inner side of the outer steel structure layer, and the outer steel structure layer and the inner grid structure are connected as a whole by pouring high-strength concrete 3-10. Compared with the existing column pile lattice column, due to the limitation of its own structure, the steel lattice column itself cannot withstand high-pressure extrusion. Especially in the case of static pile holding pressure or top pressure, the steel lattice column is easily damaged by pressure, and in order to prevent the lattice column from brittle failure, the lattice column often needs to be made of thick steel plates and angle steels for welding. The lattice column uses a large amount of steel and has limited compression and bending resistance. In the column section 3 with a composite structure in this embodiment, the outer steel structure layer and the inner grid structure are connected as a whole by pouring high-strength concrete 3-10. The inner grid structure and high-strength concrete 3-10 enhance the strength of the outer steel structure layer. The column sections 3 that form an integral whole jointly exert the compressive, bending and impact resistance properties. On the one hand, the amount of steel used in the previous steel lattice columns is greatly reduced, and the economy of the column piles is improved. On the other hand, the strength, toughness and tensile strength of the column piles are greatly improved. Not only can the brittle failure of the column sections during construction be avoided, but also the compressive, bending and impact resistance properties are combined. The static press can be used for holding or top pressing, the construction process is simpler, and the construction efficiency is significantly improved. Compared with the method of using steel sleeves to deliver piles in lattice columns, the construction depth is not limited in principle, and it can be used for deeper foundation pit support, and the scope of application is wider.

[0068] In this embodiment, the bottom plate segment 2 is used to connect with the foundation pit bottom plate, and the support segment 4 is used to connect with the support beam in the foundation pit. Since the bottom plate and the support beam are cast in place, the bottom plate segment 2 and the support segment 4 are both pre-embedded with upper and lower bidirectional steel bar connectors, which can improve the connection firmness between the foundation pit bottom plate and the column piles, and between the foundation pit support beams and the column piles, thereby ensuring the stability of the deep foundation pit support. Specifically, Figure 7 As shown, the bottom plate section 2 is pre-buried with bottom plate lower layer steel bar connectors 2-6 and bottom plate upper layer steel bar connectors 2-7. Both the bottom plate lower layer steel bar connectors 2-6 and the bottom plate upper layer steel bar connectors 2-7 are bidirectional steel bar connectors, which are used to connect with the steel bar structure in the cast-in-place foundation pit bottom plate in two directions. Figure 8 As shown, 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 bidirectional steel bar connectors, used to connect with the steel bar structure in the cast-in-place support beam in two directions. The above-mentioned bidirectional steel bar connectors can all use vertically pre-buried steel pipes to form plug-in holes on the bottom plate section 2 and the support section 4, so as to facilitate the plug-in and fixation of cast-in-place steel bars.

[0069] catch Figures 3 to 6 As shown, the assembled high-strength and toughness composite prefabricated column piles of this embodiment have an outer steel structure layer of the column section 3 including a bottom cover plate 3-1, a column section angle steel 3-2, a top cover plate 3-3, a bottom gusset plate 3-4, a top gusset plate 3-5 and a 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 through four column section angle steels 3-2. The lower ends of the four column section angle steels 3-2 are connected in sequence through the bottom gusset plate 3-4, and the upper ends are connected in sequence through the top gusset plate 3-5. A number of 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 above-mentioned outer steel structure layer is similar to that of the existing lattice column, with the difference being 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 as one, and the size and thickness of the bottom cover plate 3-1, the column section angle steel 3-2, the top cover plate 3-3, the bottom gusset plate 3-4, the top gusset plate 3-5 and the middle gusset plate 3-6 can be designed to be smaller, and the gusset plate interval can be designed to be larger, thereby reducing the amount of steel used and reducing the steel use cost of the column section.

[0070] The inner grid structure of the column section 3 includes a steel grid 3-7, an outer fiber grid 3-8 and an inner fiber grid 3-9. The outer fiber grid 3-8 is located on the outer side of the steel grid 3-7, and the inner fiber grid 3-9 is located on the inner side of the steel grid 3-7. The steel grid 3-7 is connected by main bars and stirrups. The outer fiber grid 3-8 and the inner fiber grid 3-9 are both made of FRP high-strength fiber mesh. The use of the inner and outer fiber grids can further improve the strength and toughness of the column section 3. The column section 3 is composited from the inside to the outside through four structural layers (inner fiber grid 3-9, steel grid 3-7, outer fiber grid 3-8 and outer steel structure layer, respectively), which can reduce the overall steel consumption. While improving the structural strength, toughness and tensile strength of the column pile, the production cost is reduced, so that the column pile has both compression resistance, bending resistance and impact resistance. In this embodiment, polypropylene fiber reinforcement material is added to the high-strength concrete 3-10 of the column section 3, which can improve the crack resistance and abrasion resistance of the concrete, increase the toughness of the concrete, and increase the service life of the column section 3, thus meeting the requirement 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 diagram shows the structure of the solid column section. Figure 5 and Figure 6 Shown is a schematic structural diagram of a hollow column section.

[0071] In addition, in this embodiment, the column section 3 is also equipped with a foundation pit section monitoring sensor and a wireless communication module. The foundation pit section monitoring sensor is connected to the background monitoring system through the wireless communication module to provide data support for intelligent construction, which is conducive to intelligent control of foundation pit deformation. The foundation pit section monitoring sensor includes sensors such as stress monitors, displacement monitors, and axial force detectors. Since the column section 3 can be 100% recycled, the foundation pit section monitoring sensor and wireless communication module therein can be reused, reducing the sensor reuse and maintenance costs.

[0072] Reference Figure 7As shown, in this embodiment, the bottom plate section 2 includes a rectangular steel frame and concrete filled in the rectangular steel frame, the rectangular steel frame includes 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 gusset plate 2-4, the bottom end plate 2-1 and the top end plate 2-3 are fixedly connected by four bottom plate section angle steels 2-2, and the four bottom plate section angle steels 2-2 are connected in turn by the bottom plate section gusset plate 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 gusset plate 2-4 are all connected and fixed by welding. The upper and lower ends of the four bottom plate section angle steels 2-2 are also 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 be angle steel structures, 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 by flat head bolts, so as to facilitate the rapid disassembly of the column section 3. In addition, an inner water stop plate 2-5 is pre-buried on the inner side of the bottom plate section 2, and an outer water stop plate 2-9 and a plurality of studs 2-10 are welded to the outer side of the bottom plate section 2 after the foundation pit is excavated. The inner water stop plate 2-5 is pre-installed in the bottom plate section 2, and before the construction of the foundation pit bottom plate, the bottom plate section 2 is subjected to secondary welding construction, that is, the outer water stop plate 2-9 and studs 2-10 are welded and fixed on the outer side of the bottom plate section 2, and both the outer water stop plate 2-9 and studs 2-10 can be welded to the bottom plate section angle steel 2-2, which solves the water stop problem between the column pile and the bottom plate and the connection reliability problem between the column pile and the bottom plate, and uses the foundation pile section 1 to form an effective support for the bottom plate.

[0073] Reference Figures 8 to 10As shown, in this embodiment, the above-mentioned support section 4 includes a support steel frame and concrete filled in the support steel frame. Since the support section 4 and the support beam are cast in situ to form a support node, considering the difficulty of removing the support beam after casting, a pneumatic fragmentation device 4-8 is also embedded in the support section 4, which can effectively and conveniently break and remove the support section 4 during the support removal stage, making the removal of the support beam simple and convenient, and the steel structure of the support section 4 can still be recycled for a second time. Specifically, the pneumatic fragmentation device 4-8 adopts the principle of gas explosion, 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 perfusion channel 4-8-1a, a positive electrode connecting pipe 4-8-1b and a negative electrode connecting pipe 4-8-1c. During the pressing process, the outer lead pipe 4-8-1 is blocked by the cover 4-8-2 to prevent dirt and other contaminants from entering the outer lead pipe 4-8-1; when casting the support beam, according to the position of the support beam, an external hose can be used to seal the outer lead pipe 4-8-1, and the other end of the external hose extends out of the support beam to facilitate subsequent breaking operations; when dismantling the support, liquid carbon dioxide is injected into the pneumatic fragmentation device 4-8 through the liquid carbon dioxide infusion channel 4-8-1a, and the power is turned on through the positive connecting pipe 4-8-1b and the negative connecting pipe 4-8-1c. The liquid carbon dioxide is converted into high-pressure carbon dioxide gas by electrode heating, thereby breaking the concrete of the support section 4 from the inside, facilitating the dismantling of the support beam and the recovery of the supporting steel frame in the support section 4.

[0074] catch Figure 8 As shown, in this embodiment, the support steel frame of the support section 4 includes a lower end plate 4-1, a support section angle steel 4-2, an upper end plate 4-3 and a support section gusset 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 connected in turn by the support section gusset plate 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 gusset plate 4-4 are all connected and fixed by welding technology. The upper and lower ends of the four support section angle steels 4-2 are also 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 to the angle steels at the four corners of the column section 3 by flat head bolts, so as to facilitate the rapid disassembly of the column section 3. The length of the column section 3 can be determined according to the height of the underground floor, and the number of column sections 3 used can be determined according to the depth of the foundation pit or the number of underground floors. The upper and lower adjacent column sections 3 can be connected by the support section 4.

[0075] like Fig.11 and Fig.12 As shown, the foundation pile segment 1 in this 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. Fig.11The solid square piles are shown. Fig.12 What is shown is a hollow square pile. The foundation pile segment 1 is mainly composed of concrete 1-6 and a steel cage 1-5 arranged in the concrete 1-6. Different from the existing prefabricated square piles, in order to improve the connection reliability, the lower pile head position of the foundation pile segment 1 is provided with a bottom plate 1-1 and a bottom connecting angle steel 1-2, and a bottom plate gusset plate 1-7 is provided between adjacent bottom connecting angle steels 1-2; the upper pile head position of the foundation pile segment 1 is provided with a top plate 1-3 and a top connecting angle steel 1-4, and a top plate gusset plate 1-8 is provided between adjacent top connecting angle steels 1-4. The length and width of the bottom connecting angle steel 1-2 and the top connecting angle steel 1-4 are increased, and connecting screw holes can be reserved thereon to facilitate connection with the bottom plate segment 2. The upper and lower pile head positions of the foundation pile segment 1 are provided with gusset plates to ensure the connection reliability between the foundation pile segment 1 and the upper column segment 3.

[0076] In order to further understand the technical solution of the present invention, the construction process of the assembled high-strength and toughness composite prefabricated column pile of the present invention is further explained in conjunction with the above-mentioned drawings.

[0077] S1. First, design the design drawings of the column piles at various positions through relevant engineering drawings and related materials;

[0078] S2, the prefabrication factory carries out relevant production according to the column pile design drawings; correspondingly produces the matching foundation pile segment 1, bottom plate segment 2, column segment 3 and support segment 4;

[0079] S3, the assembly factory assembles the foundation pile segment 1, the bottom plate segment 2, the column segment 3 and the support segment 4; and transports them to the construction site by vehicles;

[0080] S4, the column pile is constructed by a static press: first, the foundation pile section 1 is constructed, and then the bottom plate section 2, column section 3 and support section 4 which have been assembled in the factory are constructed in sequence; finally, the column pile is delivered to the designed elevation by a pile delivery device to complete the construction;

[0081] S5, in the support removal stage, first complete the secondary construction of the bottom plate section 2, 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 remove the column section 3 in turn, and remove the support section 4 through the pneumatic fragmentation device 4-8;

[0082] S6. Carry out matching design and reuse construction according to the next project.

[0083] The present invention discloses an assembled high-strength and tough composite prefabricated column pile. The foundation pile section located in the bottom stratum of the foundation pit 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 by the bottom plate section, and the column sections are assembled and connected by the support section, so that the column section can be easily disassembled and 100% recycled during the stage of dismantling the foundation pit. At the same time, the column section adopts a composite structure of an outer steel structure layer and an inner grid structure, which greatly reduces the steel consumption of the previous steel lattice column on the one hand, improves the economy of the column pile, and greatly improves The strength, toughness and tensile strength of the column piles are improved, which can not only avoid brittle damage of the column section during construction, but also can use static presses to hold or press, making the construction process simpler, and significantly improving the construction efficiency. In principle, the construction depth is not limited, and it can be used for deeper foundation pit support, with a wider range of applications. In addition, upper and lower bidirectional steel bar connectors are pre-embedded in the bottom plate section and the support section, which can improve the connection firmness between the foundation pit bottom plate and the column piles, and between the foundation pit support beam and the column piles, ensuring the stability of the deep foundation pit support. A pneumatic crushing device is also pre-embedded in the support section, which can effectively and conveniently break and remove the support section during the support removal stage, making the support beam removal simple and convenient, and the steel structure of the support section can still be recycled for a second time.

[0084] The present invention and its embodiments are described schematically above, which is not restrictive. The drawings show only one embodiment of the present invention, and the actual structure is not limited thereto. Therefore, if a person skilled in the art is inspired by it and creatively designs a structure and an embodiment similar to the technical solution without departing from the purpose of the invention, they shall all fall within the protection scope of the present invention.

Claims

1. An assembled high-strength and tough composite prefabricated column pile, comprising a foundation pile section (1) located in the bottom stratum of a foundation pit and a column section (3) located in the foundation pit, wherein both the foundation pile section (1) and the column section (3) are prefabricated piles, characterized in that: The upper end of the foundation pile segment (1) is assembled and connected with the lower end of the column segment (3) located at the bottom via a bottom plate segment (2), and the bottom plate segment (2) is used to connect with the bottom plate of the foundation pit; the upper and lower adjacent column segments (3) are assembled and connected via a support segment (4), and the support segment (4) is used to connect with the support beam in the foundation pit; wherein, The column section (3) adopts a structural layer composite structure, including an outer steel structure layer and an inner grid structure, wherein the inner grid structure is located inside the outer steel structure layer, and the outer steel structure layer and the inner grid structure are cast and connected as one by high-strength concrete (3-10); The bottom plate section (2) is pre-embedded with a bottom plate lower layer steel bar connector (2-6) and a bottom plate upper layer steel bar connector (2-7), and 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, which are used to connect with the steel bar structure in the cast-in-place foundation pit bottom plate in two directions; The support section (4) is pre-embedded with a support section lower layer steel bar connector (4-5) and a support section upper layer steel bar connector (4-6); both the support section lower layer steel bar connector (4-5) and the support section upper layer steel bar connector (4-6) are bidirectional steel bar connectors, and are used to connect to the steel bar structure in the cast-in-place support beam in two directions.

2. The assembled high-strength and toughness composite prefabricated column pile according to claim 1 is characterized in that: The outer steel structure layer of the column section (3) comprises a bottom cover plate (3-1), a column section angle steel (3-2), a top cover plate (3-3), a bottom gusset plate (3-4), a top gusset plate (3-5) and a 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 via four column section angle steels (3-2); the lower ends of the four column section angle steels (3-2) are connected in sequence via the bottom gusset plate (3-4), and the upper ends are connected in sequence via the top gusset plate (3-5); and a plurality of middle gusset plates (3-6) are arranged in sequence from top to bottom between the four column section angle steels (3-2).

3. The assembled high-strength and toughness composite prefabricated column pile according to claim 1 or 2, characterized in that: The inner grid structure of the column section (3) comprises a steel grid (3-7), an outer fiber grid (3-8) and an inner fiber grid (3-9), wherein the outer fiber grid (3-8) is located on the outer side of the steel grid (3-7), and the inner fiber grid (3-9) is located on the inner side of the steel grid (3-7), wherein the steel grid (3-7) is formed by connecting main bars and stirrups, and the outer fiber grid (3-8) and the inner fiber grid (3-9) are both made of FRP high-strength fiber mesh.

4. The assembled high-strength and toughness composite prefabricated column pile according to claim 3 is characterized in that: Polypropylene fiber reinforcement material is added to the high-strength concrete (3-10) of the column section (3), and the column section (3) is a solid or hollow prefabricated pile structure.

5. The assembled high-strength and toughness composite prefabricated column pile according to claim 1 is characterized in that: The column section (3) also has a foundation pit section monitoring sensor and a wireless communication module built in, and the foundation pit section monitoring sensor is connected to the background monitoring system through the wireless communication module.

6. The assembled high-strength and toughness composite prefabricated column pile according to claim 1 is characterized in that: The bottom plate section (2) comprises a rectangular steel frame and concrete filled in the rectangular steel frame, wherein 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 gusset plate (2-4), wherein the bottom end plate (2-1) and the top end plate (2-3) are fixedly connected via four bottom plate section angle steels (2-2), and the four bottom plate section angle steels (2-2) are connected in turn via the bottom plate section gusset plates (2-4); 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).

7. The assembled high-strength and toughness composite prefabricated column pile according to claim 6 is characterized in that: An inner water stop plate (2-5) is also pre-buried on the inner side of the bottom plate section (2), and an outer water stop plate (2-9) and a plurality of bolts (2-10) are welded to the outer side of the bottom plate section (2) after excavation of the foundation pit.

8. The assembled high-strength and toughness composite prefabricated column pile according to claim 1 is characterized in that: The support section (4) comprises a support steel frame and concrete filled in the support steel frame. A pneumatic fragmentation device (4-8) is also pre-buried in the support section (4). The pneumatic fragmentation device (4-8) comprises an outer lead pipe (4-8-1) and a cover (4-8-2) detachably mounted on the end of the outer lead pipe (4-8-1). A liquid carbon dioxide perfusion channel (4-8-1a), a positive electrode connecting pipe (4-8-1b) and a negative electrode connecting pipe (4-8-1c) are respectively arranged in the outer lead pipe (4-8-1).

9. The assembled high-strength and toughness composite prefabricated column pile according to claim 8 is characterized in that: 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 gusset plate (4-4); the lower end plate (4-1) and the upper end plate (4-3) are fixedly connected via four support section angle steels (4-2); the four support section angle steels (4-2) are connected in sequence via the support section gusset plates (4-4); 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 to the column section (3).

10. The assembled high-strength and toughness composite prefabricated column pile according to claim 1 is characterized in that: The foundation 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 connecting angle steel (1-2) are provided at the pile head position at the lower end of the foundation pile section (1), and a bottom plate gusset plate (1-7) is provided between adjacent bottom connecting angle steels (1-2); a top plate (1-3) and a top connecting angle steel (1-4) are provided at the pile head position at the upper end of the foundation pile section (1), and a top plate gusset plate (1-8) is provided between adjacent top connecting angle steels (1-4).

Images