A steel mesh cast-in-place pile structure and construction method suitable for high-rise buildings in karst areas

Abstract

The invention discloses a steel mesh formwork cast-in-place pile structure and a construction method suitable for high-rise buildings in karst areas. A pile hole is drilled at a construction position. A cylindrical mesh formwork component is installed in the pile hole and comprises a cylindrical steel cage and a steel mesh formwork. The steel mesh formwork is arranged outside the cylindrical steel cage to form a cylindrical space that is adapted to the inner diameter of the pile hole and vertically penetrates. A pouring device comprises a feeding conduit and a feeding device. The feeding conduit extends from the cylindrical space into the pile hole. The upper end of the feeding conduit extends out of the hole and is provided with a material receiving funnel. The feeding device is arranged on the ground and supplies material to the material receiving funnel. The hoisting device is configured as follows: before pouring, the cylindrical mesh formwork component is hoisted and lowered into the pile hole. During the pouring process, the vertical position of the feeding conduit is dynamically adjusted so that the feeding conduit maintains a constant buried depth in the continuously rising concrete.

Description

Technical Field

[0001] The invention relates to the technical field of building engineering, and in particular to a steel mesh formwork cast-in-place pile structure and a construction method suitable for high-rise buildings in karst areas. Background Art

[0002] In modern housing construction and public utility construction, pile foundations are mostly used to ensure the bearing capacity of the foundation. In karst-developed areas or when encountering connected passages such as karst caves, earth caves, and goafs, it is difficult to form a hole for pile foundation construction, and it is necessary to backfill with stone or other filling materials. During the pile pouring process, a large amount of concrete will flow into the connected passages such as karst caves, earth caves, or goafs, consuming a large amount of concrete; moreover, the wall firmness of the pile hole in the above-mentioned areas is poor. During the concrete pouring process, as the concrete is poured, the gravel and soil on the hole wall easily collapse and fall into the pile hole, mixing with the concrete of the pile body, affecting the integrity of the pile foundation and reducing the bearing capacity of the pile body. At the same time, at present, the concrete is poured inward from a fixed height of the hole mouth of the pile hole, and the speed and pressure of concrete injection are difficult to control, which not only easily causes the concrete to flow into the connected passage, but also affects the quality of the pile body injection.

[0003] At present, in order to solve the above problems, some construction methods have emerged in the prior art. The most common method is to lower a continuous closed pipe column into the pile hole and then pour concrete into the pipe column from the upper end of the closed pipe column. Although the above construction method can realize the continuous pouring construction of the pile foundation, it can prevent the gravel and soil caused by the collapse of the hole wall from entering the concrete to reduce the integrity of the pile body.

[0004] However, the above-mentioned closed pipe column construction method has the following shortcomings: concrete only enters the closed pipe column, and the concrete cannot enter the annulus between the surface of the continuous pipe column and the pile hole, so that the concrete cannot fill the entire pile hole space, and the closed pipe column is a rigid structure, which cannot adapt to some elastic changes in the inner diameter of the pile hole at the connecting channel, and cannot form a fitting and tight connection with the pile hole. The pile body cannot be firmly combined with the pile hole to form an integral structure, which affects the bearing capacity and stability of the pile body. Summary of the invention

[0005] Based on this, the present invention provides a steel mesh mold cast-in-place pile structure and construction method suitable for high-rise buildings in karst areas, so as to avoid a large amount of concrete flowing into the connected empty pile holes, and enable the pile body to adapt to the changes in the inner diameter of the pile hole and combine into a solid overall structure, thereby improving the bearing capacity and stability of the pile body.

[0006] In order to achieve the above-mentioned purpose, in a first aspect, the present invention provides a steel mesh formwork cast-in-place pile structure suitable for high-rise buildings in karst areas, comprising: a pile hole drilled at a construction location; a cylindrical mesh formwork assembly installed in the pile hole, comprising a cylindrical steel cage and a steel mesh formwork, the steel mesh formwork being arranged outside the cylindrical steel cage to form a cylindrical space that is adapted to the inner diameter of the pile hole and vertically penetrates; a pouring device comprising a feed conduit and a feed device, the feed conduit extending from the cylindrical space into the pile hole, the upper end of the feed conduit extending out of the orifice and being provided with a material receiving funnel, the feed device being arranged on the ground and feeding the material receiving funnel; a hoisting device, configured to: hoist the cylindrical mesh formwork assembly into the pile hole before pouring, and dynamically adjust the vertical position of the feed conduit during the pouring process so that the feed conduit maintains a constant sinking degree in the continuously rising concrete.

[0007] Optionally, the steel cage is provided with a plurality of steel plate clamps at vertical intervals, each of the steel plate clamps is arranged outside the steel cage, and the steel mesh mold is fixedly connected to the steel plate clamps.

[0008] Optionally, the steel mesh mold is vertically segmented, and the upper and lower ends of each segment of the steel mesh mold are respectively provided with the steel plate clamping ring, and two adjacent steel plate clamping rings are fixedly connected by a bayonet structure.

[0009] Optionally, the steel plate clamp includes a plurality of arc-shaped clamp units equally divided along the circumference, and adjacent arc-shaped clamp units are connected by elastic clamp sleeve joints to adapt to expansion and deformation during concrete pouring, so that the arc-shaped clamp is pressed against the inner wall of the pile hole.

[0010] Optionally, each of the arc-shaped clamping ring units is welded and connected to the main reinforcement of the steel cage via a support bar, and the support bar is a vertically bent structure, including a horizontal middle section, a first vertical section extending vertically from the front end of the horizontal middle section, and a second vertical section extending vertically from the rear end of the horizontal middle section. The first vertical section of the support bar is welded and fixed to the vertical main reinforcement of the steel cage, and the second vertical section is welded and fixed to the vertical surface of the steel plate clamping ring.

[0011] Optionally, the radial cross-section of the ring body of the steel plate clamping ring is an L-shaped structure, the outer edge circumferential array of the L-shaped structure is provided with protruding teeth, the outer periphery of the steel plate clamping ring is provided with a plurality of bayonet holes between the protruding teeth, and the inner side of the steel mesh mold is provided with V-shaped vertical ribs that are fixedly matched with the bayonet holes.

[0012] Optionally, the steel mesh mold includes a plurality of arc-shaped mesh mold units equally divided along the circumference, each arc-shaped mesh mold unit is matched one by one with the arc-shaped clamping ring unit, and adjacent arc-shaped mesh mold units are overlapped and loosely tied by interface binding wires, so that the steel mesh mold forms a closed cylindrical space and can adapt to radial expansion and deformation during the pouring of concrete.

[0013] Optionally, the steel mesh mold is composed of three arc-shaped mesh mold units with equal arc lengths, and the steel plate clamping ring is composed of three arc-shaped clamping ring units with equal arc lengths. The interface of the arc-shaped clamping ring unit on the same side and the interface of the arc-shaped mesh mold unit are located on the same normal line, the overlap length at the interface of each adjacent arc-shaped mesh mold unit is equal to the clamping distance between two adjacent arc-shaped clamping rings, and the overlap is loosely tied with interface binding wire to adapt to radial expansion during the pouring of concrete.

[0014] In order to achieve the above object, in a second aspect, the present invention provides a method for constructing steel mesh formwork cast-in-place piles suitable for high-rise buildings in karst areas, comprising the steps of:

[0015] S100. Select the pile hole position, and drill the pile hole to a set depth by a drilling machine;

[0016] S200. A wire rope is connected to the bottom of the lifting hook of the lifting equipment, a lifting pole is connected to the bottom of the wire rope, the lifting pole is connected to the top of the cylindrical steel cage through the lifting rod, and the cylindrical mesh form assembly is lifted and lowered into the pile hole;

[0017] S300. The feed conduit is hoisted by the hoisting equipment and lowered into the pile hole from the center of the cylindrical space of the cylindrical mesh mold assembly, with the lower end of the feed conduit extending near the bottom of the hole and the upper end extending out of the hole opening;

[0018] S400. The feeding device delivers concrete from the receiving hopper to the pile hole through the feeding conduit;

[0019] S500. As the concrete in the pile hole rises, the lifting equipment dynamically supplies the material supply conduit so that the sinking degree of the material supply conduit in the concrete remains unchanged until the pile foundation construction is completed.

[0020] Optionally, the cylindrical mesh mold assembly includes a steel plate clamp and a steel mesh mold, the steel plate clamp is composed of a plurality of equal-length arc-shaped clamp units, and adjacent arc-shaped clamp units are connected by elastic clamp sleeve joints; the steel mesh mold is composed of a plurality of equal-length arc-shaped mesh membrane units, adjacent edges of adjacent steel mesh mold structural units are overlapped and tied by interface binding wires, and each arc-shaped clamp unit is matched with each arc-shaped mesh mold unit one by one; the construction method includes:

[0021] Before pouring concrete, the steel plate clamp ring and the steel mesh mold of the steel mesh mold assembly are in a contracted state and are inserted into the pile hole in a state smaller than the pile hole size;

[0022] During the pouring of concrete, due to the external expansion force of the concrete, the steel plate clamp ring and the steel mesh mold of the steel mesh mold assembly expand outwards respectively and are pressed against the inner wall of the pile hole.

[0023] The technical advantages of the steel mesh formwork cast-in-place pile structure and construction method for high-rise buildings in karst areas provided by the present invention are at least reflected in:

[0024] Firstly, by setting up a steel mesh formwork as a barrier in the cylindrical steel cage, it is effectively prevented that a large amount of slurry containing stones is lost into the connecting channel, and impurities such as gravel and soil on the hole wall are prevented from entering the concrete pile body, thereby avoiding material waste and improving the overall quality of the pile body.

[0025] Secondly, during the concrete pouring process, the steel mesh mold is deformed and pressed against the side wall of the pile hole, which not only increases the friction resistance on the pile side, but also allows the concrete slurry to penetrate through the steel mesh mold into the space between the hole wall and the steel mesh mold. After solidification, the pile body and the wall of the pile hole form a solid integrated structure, thereby improving the bearing capacity.

[0026] Thirdly, during the concrete pouring process, the vertical position of the feed duct is dynamically adjusted through the lifting equipment, so that the feed duct maintains a constant sinking degree, effectively controlling the speed and pressure of concrete input, avoiding excessive concrete pressure and large-scale loss to the connecting channel, and maintaining the quality of pile pouring. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] By reading the detailed description of the preferred embodiment below, various other advantages and benefits will become clear to those of ordinary skill in the art. The accompanying drawings are only used for the purpose of illustrating the preferred embodiment and are not considered to be limitations of the present invention. In addition, the same reference symbols are used to represent the same components throughout the accompanying drawings.

[0028] In the attached picture:

[0029] Figure 1 It is an elevation view of an embodiment of the steel mesh formwork cast-in-place pile structure applicable to high-rise buildings in karst areas;

[0030] Figure 2 A schematic structural diagram of an embodiment of the connection between the provided steel mesh form and the steel cage;

[0031] Figure 3 It is a schematic diagram of the structure of the provided steel mesh mold and the steel plate clamp ring;

[0032] Figure 4 It is a schematic diagram of the connection structure of the main reinforcement of the steel cage, the steel plate clamp ring and the steel mesh mold provided;

[0033] Figure 5 It is a structural schematic diagram of an embodiment of the provided support bar;

[0034] Figure 6 It is a structural schematic diagram of an embodiment of the provided steel cage hoisting sling;

[0035] Figure 7 The schematic diagram of the status of the pouring construction process of the steel mesh formwork cast-in-place piles for high-rise buildings is provided.

[0036] Figure 8The present invention is a flowchart of an embodiment of a steel mesh formwork cast-in-place pile construction method applicable to high-rise buildings in karst areas.

[0037] Description of the accompanying drawings:

[0038] 1-pile hole, 11-steel casing, 12-karst hole;

[0039] 2-cylindrical mesh mold assembly, 21-vertical main reinforcement, 22-supporting reinforcement, 23-steel plate clamp, 24-clamp sleeve joint, 25-steel mesh mold, 26-bayonet, 27-interface binding wire;

[0040] 3-lifting equipment, 31-wire rope, 32-lifting pole, 33-lifting rod;

[0041] 4-feeding device, 41-receiving funnel, 42-feeding conduit. DETAILED DESCRIPTION

[0042] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0043] like Figures 1 to 7 As shown, the present invention provides an embodiment of a steel mesh formwork cast-in-place pile structure suitable for high-rise buildings in karst areas, comprising a pile hole, a cylindrical mesh formwork assembly, a casting device and a hoisting device.

[0044] The pile hole 1 is drilled at the construction location. Before drilling, a steel casing is buried at the hole mouth of the pile hole to keep the hole mouth structure near the ground stable, creating basic conditions for subsequent construction such as lowering the cylindrical mesh formwork component 2 and pouring concrete.

[0045] The cylindrical mesh mold assembly 2 is installed in the pile hole 1, and includes a cylindrical steel cage and a steel mesh mold 25. The steel mesh mold 25 is arranged outside the cylindrical steel cage to form a cylindrical space that is adapted to the inner diameter of the pile hole 1 and vertically penetrates. The steel mesh mold receives the external expansion effect of concrete during the pouring process, and can produce a small range of elastic deformation and adhere to the hole wall of the pile hole 1.

[0046] The pouring equipment includes a feed conduit 42 and a feed device 4. The feed conduit 42 extends from the cylindrical space into the pile hole 1. The upper end of the feed conduit 42 extends out of the hole and is provided with a receiving funnel 41. The feed device 4 is arranged on the ground and feeds the receiving funnel 41. The feed conduit is movably connected to the hook of the lifting equipment and can be adjusted up and down by driving the lifting equipment 3.

[0047] The hoisting device 3 is configured to: hoist the cylindrical mesh form assembly 2 into the pile hole 1 before pouring, and dynamically adjust the vertical position of the supply conduit 42 during the pouring process so that the supply conduit 42 maintains a constant sinking degree in the continuously rising concrete.

[0048] like Figure 8 As shown, based on a provided steel mesh mold cast-in-place pile structure suitable for high-rise buildings in karst areas, an embodiment of a steel mesh mold cast-in-place pile construction method suitable for high-rise buildings in karst areas provided by the present invention includes the steps of:

[0049] S100. Select the location of the pile hole 1. Before drilling, bury the steel casing 11 in the pile hole 1, and drill the pile hole 1 to a set depth by a drilling machine;

[0050] S200. The hook of the lifting device 3 is connected to the wire rope 31 below, the wire rope 31 is connected to the lifting pole 32 below, the lifting pole 32 is connected to the top of the cylindrical steel cage through the lifting rod 33, and the cylindrical mesh mold assembly 2 is hoisted into the pile hole 1;

[0051] S300. The feed conduit 42 is hoisted by the hoisting device 3, and is lowered into the pile hole 1 by the center of the cylindrical space of the cylindrical mesh mold assembly 2, and the lower end of the feed conduit 42 extends near the bottom of the hole and the upper end extends outside the hole;

[0052] S400. The feeding device 4 delivers concrete to the pile hole 1 through the feeding conduit 42 by the receiving hopper 41;

[0053] S500. As the concrete in the pile hole 1 rises, the hoisting device 3 dynamically supplies the feed conduit 42 so that the sinking degree of the feed conduit 42 in the concrete remains unchanged until the pile foundation construction is completed.

[0054] Based on the above provided cast-in-place pile structure and construction method applicable to high-rise buildings in karst areas, a steel mesh mold is added to the periphery of the steel cage to form a simple template to the side wall of the pile hole when pouring concrete. The steel mesh mold is used to block the slurry containing stones, effectively preventing a large amount of slurry from flowing into the connecting channel, avoiding material waste, and preventing impurities such as gravel and soil on the hole wall from entering the concrete pile body, thereby improving the overall quality of the pile body. At the same time, the feed conduit extends into the pile hole through the center of the cylindrical mesh mold. During the pouring process, the vertical position of the feed conduit is dynamically adjusted by the hoisting equipment so that the feed conduit maintains a constant sinking degree in the rising concrete, and can control the speed and pressure of concrete input, avoiding excessive concrete pressure and a large amount of concrete loss to the connecting channel, and maintaining the quality of pile body pouring.

[0055] like Figure 2 and Figure 3As shown, in some embodiments, the steel cage is provided with a plurality of steel plate clamps 23 at intervals along the vertical direction, each of the steel plate clamps 23 is arranged outside the steel cage, and the steel mesh mold 25 is fixedly connected to the steel plate clamps 23. Further, the steel mesh mold 25 is vertically segmented, and the upper and lower ends of each segment of the steel mesh mold 25 are respectively provided with the steel plate clamps 23, and two adjacent steel plate clamps 23 are fixedly connected by a bayonet 26 structure. Based on this structural mode, the steel plate clamps 23 connected to the steel cage play a supporting role on the steel mesh mold, maintain the structural stability and bearing capacity of the steel mesh mold, facilitate the lowering of the cylindrical mesh mold assembly into the pile hole, and can bear the large impact force generated by the concrete during the pouring process.

[0056] like Figure 2 As shown, in some embodiments, the steel plate clamp 23 includes a plurality of arc-shaped clamp units equally divided along the circumference, and adjacent arc-shaped clamp units are connected by elastic clamp sleeve joints 24, so as to adapt to expansion deformation during the pouring of concrete, so that the arc-shaped clamp units are pressed against the inner wall of the pile hole 1. A plurality of arc-shaped clamp units are provided and connected by an annular clamp sleeve joint, so that the steel plate clamp units can produce elastic deformations in different directions, so as to adapt to the scene where the gaps from the pile hole wall to the steel plate clamp unit to the adjacent pile hole wall are of different sizes, thereby improving the adaptability to the pile hole shape.

[0057] like Figure 2 and Figure 3 As shown, in some embodiments, the steel mesh mold 25 includes a plurality of arc-shaped mesh mold units equally divided along the circumference, each arc-shaped mesh mold unit is matched with the arc-shaped clamping ring unit one by one, and adjacent arc-shaped mesh mold units are overlapped and loosely tied by interface binding wires 27, so that the steel mesh mold 25 forms a closed cylindrical space and can adapt to radial expansion and deformation during the pouring of concrete.

[0058] like Figure 2 and Figure 3 As shown, in a specific embodiment, the steel mesh mold 25 is composed of three arc mesh mold units with equal arc lengths, the steel plate clamp 23 is composed of three arc clamp units with equal arc lengths, the interface of the arc clamp unit on the same side and the interface of the arc mesh mold unit are located on the same normal line, the overlap length at the interface of each adjacent arc mesh mold unit is equal to the distance between the clamps 26 of two adjacent arc clamps, and the overlap is loosely tied with interface binding wires 27 to adapt to radial expansion during the pouring of concrete. Based on the structure provided in the above embodiment, the construction method includes:

[0059] Before pouring concrete, the steel plate clamp ring 23 and the steel mesh mold 25 of the steel mesh mold 25 assembly are in a contracted state, and are inserted into the pile hole 1 in a state smaller than the size of the pile hole 1; during the pouring of concrete, the steel plate clamp ring 23 and the steel mesh mold 25 of the steel mesh mold 25 assembly expand outwards and are pressed against the inner wall of the pile hole 1 due to the external expansion force of the concrete.

[0060] Moreover, during the process of pouring concrete, the steel plate clamp ring and the steel mesh mold are deformed and pressed against the side wall of the pile hole, which not only increases the friction resistance on the pile side, but also allows the concrete slurry to penetrate into the space between the hole wall and the steel mesh mold through the mesh holes of the steel mesh mold. After solidification, the pile body containing the steel mesh mold and the hole wall of the pile hole form a solid integrated structure, thereby improving the bearing capacity of bored piles constructed in complex geology.

[0061] like Figure 4 and Figure 5 As shown, further, in some embodiments, each of the arc-shaped collar units is welded to the main reinforcement of the steel cage through a support bar 22. The support bar 22 is a vertical bending structure, including a horizontal middle section, a first vertical section extending vertically from the front end of the horizontal middle section, and a second vertical section extending vertically from the rear end of the horizontal middle section. The first vertical section of the support bar 22 is welded and fixed to the vertical main reinforcement 21 of the steel cage, and the second vertical section is welded and fixed to the vertical surface of the steel plate collar 23. Through the structural design of the support bar, the vertical rigidity of the connection between the elastic collar unit and the main reinforcement of the steel cage is maintained, and radial deformation can be generated by the external expansion force of the concrete, so as to achieve the dual functions of supporting the steel mesh mold and adapting to deformation.

[0062] like Figure 2 and Figure 3 As shown, further, in some embodiments, the radial cross-section of the ring body of the steel plate clamp 23 is an L-shaped structure, the outer edge circumferential array of the L-shaped structure is provided with convex teeth, the outer periphery of the steel plate clamp 23 is provided with a plurality of bayonet holes 26 between the convex teeth, and the inner side of the steel mesh mold 25 is provided with V-shaped vertical ribs that are fixedly matched with the bayonet holes 26. Through this structure, the firmness of the connection between the steel plate clamp and the steel mesh mold is improved.

[0063] The present invention provides a steel mesh formwork cast-in-place pile structure and a construction method suitable for high-rise buildings in karst areas, so as to avoid a large amount of concrete loss during the construction of cast-in-place piles with connected empty passage pile holes, thereby avoiding material waste and reduced pile quality, and adapting to changes in the inner diameter of the empty passage to form a firm overall structure, so as to achieve uniform distribution of concrete slurry between the pile body and the pile hole, so as to improve the bearing capacity and stability of the pile body.

[0064] The steel mesh formwork cast-in-place pile structure and construction method for high-rise buildings in karst areas can be used for the construction of pile foundations of various construction projects and municipal common projects in karst development areas, and are also suitable for pile foundation construction when encountering connected passages such as karst caves, soil caves, and goafs.

[0065] In order to further illustrate the technical solution of the present invention, the following is a specific on-site embodiment to illustrate the steel mesh formwork cast-in-place pile structure and construction method applicable to high-rise buildings in karst areas provided by the present invention.

[0066] like Figures 1 to 7 As shown, the present invention provides a steel mesh mold cast-in-place pile structure suitable for high-rise buildings in karst areas, comprising a pile hole system 1, a steel cage and steel mesh mold system 2, a hoisting system 3, a cast concrete system 4, etc.; the pile hole system comprises a pile hole 1, a steel casing 11, and a karst hole 12. The pile hole 1 is drilled by a drilling machine, and the steel casing 11 is buried at the hole mouth before drilling; the steel cage and steel mesh mold system comprises a steel cage 2, a steel cage main reinforcement 21, a support reinforcement 22, a steel plate clamp 23, a clamp sleeve joint 24, a steel mesh mold 25, a clamp 26, and an interface binding wire 27. The steel plate clamp 23 is arranged on the periphery of the steel cage 2, and the steel plate clamp 2 3 is connected to the main reinforcement 21 of the steel cage by a foot reinforcement 22, and both ends are welded and fixed. The steel plate clamp ring 23 is divided into three sections of equal arc length in the circumferential direction and made into a circle shape. A retractable clamp sleeve joint 24 is arranged between the sections. The V-shaped vertical ribs of the steel mesh mold 25 are clamped in the clamping mouth around the outer edge of the steel plate clamp ring 23 to form a simple template around the pile to prevent the poured concrete from flowing into the karst hole 12. The steel mesh mold 25 is first rolled into a cylindrical shape and divided into three sections of equal arc length along the circumferential direction. Adjacent sections are overlapped, and the inner and outer molds at the overlap are bounded by interface binding wires 27. The vertical sections are processed in sections, and double steel plate clamp rings 23 are arranged at the joints to form a firm clamping mouth 26 structure.

[0067] like Figure 6 and Figure 7 As shown, the hoisting system includes a truck crane 3, a steel wire rope 31, a lifting pole 32, and a lifting rod 33. The truck crane 3 is supported on the ground near the hole mouth. The steel wire rope 31 is connected below the hook of the truck crane 3. The lifting pole 32 is connected below the steel wire rope. The lifting pole is connected to the top of the steel cage through the lifting rod 33. The truck crane lifts the steel cage 2 and the outer steel mesh mold 25 and installs them into the pile hole 1. The concrete pouring system includes a steel pipe 4, a large funnel 41, and a concrete mixer 42. The steel pipe 4 is lowered into the steel cage 2, with the bottom opening about 30 cm from the bottom of the hole and the top above the ground. The large funnel 41 is installed at the top of the steel pipe 4. The concrete mixer 42 transports and pours concrete into the large funnel. The steel pipe is lifted up section by section and concrete is poured to complete the pile foundation construction.

[0068] like Figure 4 and Figure 5As shown, in some specific embodiments on site, the support bar 22 is made of Φ10mm steel bars, one end of which is welded to the main steel cage bar 21, supporting the steel plate clamp 23 outward, and the outer end is welded to the "L"-shaped vertical edge of the steel plate clamp 23. Each section of the steel plate clamp 23 is supported by two support bars 22. The steel plate clamp 23 is made of Q235 steel, with an "L"-shaped cross section, a wall thickness of not less than 2mm, and is made into a circle. A convex tooth is set on the outer edge of the "L"-shaped horizontal edge, and a bayonet and a barb are set in the middle of the convex tooth. The bayonet can clamp the V-shaped vertical rib on the steel mesh mold 25.

[0069] like Figure 2 and Figure 3 As shown, the steel plate clamp 23 is divided into three sections of equal arc length along the circumference, and a retractable clamp sleeve joint 24 is arranged between adjacent sections, forming a circle shape after assembly; when pouring concrete, the steel plate clamp 23 can expand a small amount synchronously with the steel mesh mold.

[0070] like Figure 2 As shown, in some specific embodiments on site, the steel mesh mold 25 is made of Q195A steel, which is a steel mesh made of galvanized thin steel plate through punching, stretching and rolling, and has a weight of ≥1.5kg / m 2 , V-shaped vertical ribs are arranged in parallel on the steel plate mesh, with a spacing of 200 to 300 mm. The steel mesh mold 25 is rolled into a cylindrical shape by a plate rolling machine, and the rolling diameter is the same as the design diameter of the pile foundation. When the steel mesh mold 25 is rolled, it is divided into three sections of equal arc length along the circumferential direction. The three interfaces are overlapped. The interface position is on the same normal line as the clamping ring joint 24. The overlap length is the length between two adjacent clamping holes 26. The inner and outer molds of the overlap interface are tied with interface binding wires 27. The steel mesh mold is not connected to the steel plate clamping ring 23 within the overlap length range. The steel mesh mold 25 not only forms a closed simple template structure, but also can adapt to a small amount of expansion and fill the pile hole 1. In some specific embodiments on site, each section of the steel mesh mold 25 is 2.0 m long vertically. The two sections of the steel mesh mold are aligned at the joint, and a double steel plate clamping ring 23 is set to form a firm clamping hole 26 structure, forming a continuous, cylindrical steel mesh mold 25 vertically.

[0071] like Figure 1 As shown, in some specific embodiments on site, the truck crane used as the lifting equipment 3 is a 25t rated load truck crane, which is supported on the compacted ground near the hole mouth, and a steel wire rope 31 is connected under the hook of the truck crane 3, and a lifting pole 32 is connected under the steel wire rope. The lifting pole is connected to the top of the steel cage through a lifting rod 33, and the truck crane lifts the steel cage 2 and the outer steel mesh mold 25 and installs them into the pile hole 1. The lifting rod 33 is made of Φ16mm HPB300 steel bars, a total of 2, the lower end is double-sidedly welded to the main steel cage bar 21, and a lifting ring is set at the upper end, which is connected to the ear hole of the lifting pole 32.

[0072] In some specific embodiments on site, the steel conduit 42 is lowered into the steel cage 2, with the bottom opening about 30 cm from the bottom of the hole, and a large funnel 41 is installed above the ground at the top, and a concrete mixer truck as the feeding device 4 transports and pours concrete into the large funnel. The concrete surface of the cast-in-place pile gradually rises, and the steel conduit 4 is synchronously lifted and removed section by section, and is always kept buried at a depth of 4 to 6 m in the concrete, and the poured concrete exceeds the designed elevation of the pile top by 0.5 to 1.0 m, completing the steel mesh mold cast-in-place pile construction.

[0073] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A steel mesh cast-in-place pile structure suitable for high-rise buildings in karst areas, characterized in that: include: A pile hole (1) is drilled at the construction location; A cylindrical mesh mold assembly (2) is installed in the pile hole (1), comprising a cylindrical steel cage and a steel mesh mold (25), wherein the steel mesh mold (25) is arranged outside the cylindrical steel cage to form a cylindrical space that matches the inner diameter of the pile hole (1) and is vertically connected; The pouring equipment comprises a feeding conduit (42) and a feeding device (4), wherein the feeding conduit (42) extends from the cylindrical space into the pile hole (1), the upper end of the feeding conduit (42) extends out of the hole and is provided with a receiving funnel (41), and the feeding device (4) is arranged on the ground and supplies materials to the receiving funnel (41); The hoisting device (3) is configured to: hoist the cylindrical mesh form assembly (2) into the pile hole (1) before pouring, and dynamically adjust the vertical position of the supply conduit (42) during the pouring process so that the supply conduit (42) maintains a constant sinking degree in the continuously rising concrete.

2. The steel mesh cast-in-place pile structure suitable for high-rise buildings in karst areas according to claim 1 is characterized in that: The steel cage is provided with a plurality of steel plate clamps (23) at intervals in the vertical direction, each of the steel plate clamps (23) is arranged outside the steel cage, and the steel mesh mold (25) is fixedly connected to the steel plate clamps (23).

3. The steel mesh cast-in-place pile structure suitable for high-rise buildings in karst areas according to claim 2 is characterized in that: The steel mesh mold (25) is vertically arranged in sections, and the upper and lower ends of each section of the steel mesh mold (25) are respectively provided with the steel plate clamping ring (23), and two adjacent steel plate clamping rings (23) are fixedly connected via a bayonet (26) structure.

4. The steel mesh cast-in-place pile structure suitable for high-rise buildings in karst areas according to claim 3 is characterized in that: The steel plate clamp (23) comprises a plurality of arc-shaped clamp units equally divided along the circumference, and adjacent arc-shaped clamp units are connected by elastic clamp sleeve joints (24) so ​​as to adapt to expansion and deformation during the concrete pouring process, so that the arc-shaped clamp units are pressed tightly against the inner wall of the pile hole (1).

5. The steel mesh cast-in-place pile structure suitable for high-rise buildings in karst areas according to claim 4 is characterized in that: Each of the arc-shaped clamping ring units is welded to the main reinforcement of the steel cage through a support reinforcement (22). The support reinforcement (22) is a bent structural reinforcement, comprising a horizontal middle section, a first vertical section extending vertically from the front end of the horizontal middle section, and a second vertical section extending vertically from the rear end of the horizontal middle section. The first vertical section of the support reinforcement (22) is welded and fixed to the vertical main reinforcement (21) of the steel cage, and the second vertical section is welded and fixed to the vertical surface of the steel plate clamping ring (23).

6. The steel mesh cast-in-place pile structure suitable for high-rise buildings in karst areas according to claim 2 is characterized in that: The radial cross-section of the ring body of the steel plate clamp (23) is an L-shaped structure, and the outer edge of the L-shaped structure is provided with a convex tooth array. The outer periphery of the steel plate clamp (23) is provided with a plurality of bayonet holes (26) between the convex teeth, and the inner side of the steel mesh mold (25) is provided with a V-shaped vertical rib that is fixedly matched with the bayonet holes (26).

7. The steel mesh cast-in-place pile structure suitable for high-rise buildings in karst areas according to claim 5 is characterized in that: The steel mesh mold (25) comprises a plurality of arc-shaped mesh mold units equally divided along the circumference, each arc-shaped mesh mold unit is matched with an arc-shaped clamping ring unit one by one, and adjacent arc-shaped mesh mold units are overlapped and loosely tied by interface binding wires (27), so that the steel mesh mold (25) forms a closed cylindrical space and can adapt to radial expansion and deformation during the pouring of concrete to fill the pile hole.

8. The steel mesh cast-in-place pile structure suitable for high-rise buildings in karst areas according to claim 2 is characterized in that: The steel mesh mold (25) is composed of three arc mesh mold units of equal arc length, and the steel plate clamp (23) is composed of three arc clamp units of equal arc length. The interface of the arc clamp unit on the same side is located on the same normal line as the interface of the arc mesh mold unit. The overlapping length at the interface of each adjacent arc mesh mold unit is equal to the distance between the clamping openings (26) of two adjacent arc clamps. The overlapping part is loosely tied with an interface binding wire (27) to adapt to radial expansion during the pouring of concrete and fill the pile hole.

9. A construction method for realizing a steel mesh cast-in-place pile structure suitable for high-rise buildings in karst areas as claimed in any one of claims 1 to 8, characterized in that: Includes steps: S100. Select the pile hole (1) position, before drilling, bury the steel casing (11) in the pile hole (1), and drill the pile hole (1) to a set depth by a drilling machine; S200. A wire rope (31) is connected to the bottom of the hook of the lifting device (3), a lifting pole (32) is connected to the bottom of the wire rope (31), and the lifting pole (32) is connected to the top of the cylindrical steel cage through the lifting rod (33), and the cylindrical mesh mold assembly (2) is hoisted into the pile hole (1); S300. The feed conduit (42) is hoisted by the hoisting device (3) and lowered into the pile hole (1) from the center of the cylindrical space of the cylindrical mesh mold assembly (2), and the lower end of the feed conduit (42) extends to the vicinity of the bottom of the hole and the upper end extends out of the hole opening; S400. The feeding device (4) conveys concrete from the receiving hopper (41) through the feeding conduit (42) to the pile hole (1); S500. As the concrete in the pile hole (1) rises, the hoisting equipment (3) dynamically supplies the feed conduit (42) so that the sinking degree of the feed conduit (42) in the concrete remains unchanged until the pile foundation construction is completed.

10. The method for constructing steel mesh cast-in-place piles for high-rise buildings in karst areas according to claim 9, characterized in that: The cylindrical mesh mold assembly (2) comprises a steel plate clamp (23) and a steel mesh mold (25), wherein the steel plate clamp (23) is composed of a plurality of arc-shaped clamp units of equal length, and adjacent arc-shaped clamp units are connected by elastic clamp sleeve joints (24); the steel mesh mold (25) is composed of a plurality of arc-shaped mesh membrane units of equal length, and adjacent edges of adjacent steel mesh mold (25) structural units are overlapped and tied by interface binding wires (27), and each arc-shaped clamp unit is matched with each arc-shaped mesh mold unit one by one; The construction method comprises: Before pouring concrete, the steel plate clamp ring (23) and the steel mesh mold (25) of the steel mesh mold (25) assembly are in a contracted state and are inserted into the pile hole (1) in a state smaller than the size of the pile hole (1); During the pouring of concrete, due to the external expansion force of the concrete, the steel plate clamping ring (23) and the steel mesh mold (25) of the steel mesh mold (25) assembly expand outwards and are pressed against the inner wall of the pile hole (1).

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