A YCMG method composite precast pile column and its construction method

Abstract

This invention discloses a YCMG method composite precast pile and its construction method, belonging to the field of pile foundation technology. The column pile of this invention includes a precast pile, a lattice column, a cement-soil pile, and a rigid enlarged body connector. The pile hole construction is low-noise, requires no excavation, and produces no mud, making it environmentally friendly. The precast pile is installed to the bottom of the pile hole, forming a cement-soil pile around it. At the junction of the precast pile and the lattice column, concrete wrapped around the reinforcing cage connector is poured to form a rigid enlarged body connector, solving the problem of poor shear resistance at the connection node and significantly improving the bearing capacity of the column pile. Compared with existing column piles, the construction method is simpler, construction efficiency is increased by 200%–300%, the quality and safety at the junction of the precast pile and the lattice column are reliably guaranteed, the bearing capacity of the column pile foundation is increased by 10%–50%, green and pollution-free construction is achieved, and construction costs are significantly reduced, resulting in significant economic and social benefits.

Description

Technical Field

[0001] This invention relates to a column pile and its construction method, and more specifically, to a column pile of YCMG composite precast pile and its construction method. Background Technology

[0002] With the progress and development of national economic construction, the scale and area of ​​foundation pits are getting larger and larger, the length and width of foundation pit supports are also increasing, the number of column piles is also increasing, and the requirements are becoming more and more stringent. As the support point of the support, the column piles are not only subjected to compression and tension, but also torsion and shear.

[0003] Currently, the main types of column piles are as follows: cast-in-place piles + lattice columns, steel-concrete column piles, grouting and expanding steel-concrete pipe column piles, supporting columns combining steel-concrete pipe columns and prestressed pipe piles, reinforced cement-soil steel composite column piles, and column piles combining prestressed high-strength concrete pipe piles and steel lattice columns.

[0004] I. Cast-in-place piles + lattice columns

[0005] Cast-in-place piles with lattice columns are mainly formed by drilling and grouting of bored piles, and lattice columns are inserted into the reinforcing cage of the cast-in-place piles to form a conventional column pile form.

[0006] The main disadvantages of the cast-in-place pile + lattice column type of column pile are: serious mud pollution, excavation construction, and the need to transport the excavated soil, resulting in high costs; secondly, the diameter of the cast-in-place pile is affected by the size of the lattice column, and the design of the cast-in-place pile diameter is relatively large, resulting in material waste; thirdly, during the construction of the base slab and floor slab, the cement and soil mixed inside the lattice column are difficult to remove, and it is not easy to insert the reinforcing steel, making construction difficult.

[0007] II. Steel-concrete composite column piles

[0008] The reinforced concrete column pile includes a precast pipe pile, an H-steel pile, and an enlarged section. The enlarged section is located at the top of the precast pipe pile, and the H-steel pile is installed on the enlarged section. The end of the H-steel pile facing the precast pipe pile is called the steel pile connection end, and the end of the precast pipe pile facing the H-steel pile is called the pipe pile connection end. When the reinforced concrete column pile extends vertically, in the horizontal direction, the outer circumference of the enlarged section extends outward beyond the outer circumference of the precast pipe pile.

[0009] The main disadvantages of reinforced concrete column piles are: Firstly, the lower part uses simple pipe piles, which have poor shear resistance, especially at the joints, which are structurally weak points and prone to failure under significant torsional and shear forces. Secondly, the upper part uses H-beams, which, due to the limited asymmetric moment of inertia, make the pile more susceptible to instability and failure on the side with the smaller moment of inertia when subjected to large torsional and shear forces. Furthermore, the bearing capacity of the pipe piles is limited by their diameter, requiring longer designs that can result in an excessively large length-to-diameter ratio, making them prone to instability and failure.

[0010] III. Grouting and Expansion of Steel-Pipe Concrete Column Piles

[0011] Grouting-expanded steel-concrete composite piles consist of steel-concrete composite pile segments and steel-concrete composite column segments. The steel-concrete composite pile segments are constructed using a drilling and grouting expansion process, forming a pile side zone outside the outer perimeter of the pile segment. During drilling, a mud-replacement grouting pipe is attached externally for grouting into the pile side zone. The steel-concrete composite pile segment includes a grouting expansion device located at the bottom of the segment. This configuration, through cement grout replacement of the pile side mud and grouting expansion, increases the lateral resistance of the steel-concrete composite pile segment.

[0012] The main disadvantages of grouting and expanding steel pipe concrete column piles are: because they are drilled and implanted, mud is generated, causing serious mud pollution; and because they are made entirely of steel pipes from top to bottom, they are more expensive than precast piles and cast-in-place piles.

[0013] IV. Supporting columns for the combination of steel-concrete composite columns and prestressed concrete pipe piles

[0014] This supporting column, a combination of steel-concrete composite column and prestressed concrete pipe pile, includes a steel-concrete composite column, prestressed concrete pipe piles, and connectors. The steel pipe column and prestressed concrete pipe piles are connected to the connectors, forming a unified structure. Concrete is then poured inside the steel pipe column to form the steel-concrete composite column. The connectors utilize a concrete-core steel structure. The upper and lower steel pipes at both ends are inserted to a certain depth into the holes of the steel pipe column and prestressed concrete pipe piles, forming reliable hinged joints that meet the column's shear and bearing capacity requirements. The connectors are also fixed to the steel pipe column and prestressed concrete pipe piles using welding and bolts, providing a certain level of shear and bending bearing capacity.

[0015] The main disadvantages of using a combination of steel-concrete composite columns and prestressed concrete pipe piles are as follows: Because the steel pipe is inserted into the pipe pile at the connection point, its shear and torsional resistance are determined by the torsional and shear resistance of the pipe pile itself. When the column is subjected to significant torsional and shear forces, the poor shear resistance of the pipe pile itself can easily lead to quality issues at the joint. Furthermore, the bearing capacity provided by the pipe pile is limited by its diameter, requiring a relatively long pipe pile design, which can easily result in an excessively large length-to-diameter ratio, making it prone to instability and failure.

[0016] V. Reinforced Cement-Soil Steel Composite Column Pile

[0017] The reinforced cement-soil steel composite column pile includes a jet grouting cement-soil pile body formed in the pile hole, a steel cage located in the jet grouting cement-soil pile body, and an H-beam welded to the steel cage. The H-beam extends upward from the jet grouting cement-soil pile body to form a column, which is used to support the horizontal support in the foundation pit. The steel cage includes longitudinal bars and stirrups wrapped around the longitudinal bars.

[0018] The main disadvantages of reinforced cement-soil steel composite column piles are as follows: First, the lower part of the column pile is a cement-soil mixing pile formed by jet grouting. Although steel bars are placed in the cement-soil body, due to the low strength of cement-soil, the cement-soil mixing pile is prone to failure when the column pile is subjected to large torsional and shear forces, and cannot effectively exert its bearing capacity, which can easily lead to quality problems. Second, the upper part adopts the form of H-beams. Due to the limited asymmetrical moment of inertia of the H-beams, when the column pile is subjected to large torsional and shear forces, the side with the smaller moment of inertia is prone to instability and failure.

[0019] VI. Column piles combining prestressed high-strength concrete pipe piles and steel lattice columns

[0020] A column pile consisting of a prestressed high-strength concrete pipe pile and a steel lattice column includes an upper steel lattice column and a lower prestressed high-strength concrete pipe pile; the prestressed high-strength concrete pipe pile is inserted into the steel lattice column; the steel lattice column and the prestressed high-strength concrete pipe pile are connected by an end plate, and the steel lattice column is provided with a steel lattice column end plate; the end of the prestressed high-strength concrete pipe pile is provided with a pipe pile end plate, and the steel lattice column end plate is fixedly connected to the pipe pile end plate.

[0021] The main disadvantages of the combination of prestressed high-strength concrete pipe piles and steel lattice columns are as follows: because the lattice column is wrapped around the pipe pile at the connection point, when the pipe pile diameter is large, the side length of the lattice column becomes very large, far exceeding its designed bearing capacity, resulting in a great waste of materials; at the same time, when the column pile is subjected to large torsional and shear forces, the shear resistance of the pipe pile itself is poor, and quality problems are prone to occur at the joint; on the other hand, the bearing capacity provided by the pipe pile is limited by its diameter, and the pipe pile design needs to be long, which can easily lead to an excessive length-to-diameter ratio and instability failure.

[0022] Based on the structural and technological characteristics of existing column piles, it can be seen that existing column piles mainly have the following problems:

[0023] ① Excavation work generates sludge, which causes serious environmental pollution, and also generates a lot of noise and has low efficiency.

[0024] ②Serious material waste and high manufacturing costs;

[0025] ③ The column piles have poor resistance to torsion and shear, and the connection nodes are weak, making them prone to instability and failure. Summary of the Invention

[0026] 1. The technical problem that the invention aims to solve

[0027] The purpose of this invention is to solve the aforementioned problems of existing column piles and to provide a YCMG method composite precast pile and its construction method. Using the technical solution of this invention, the pile hole is formed by pressing an outer casing with a discardable pile tip into the soil using a static pressure pile driver or a non-resonant hydraulic vibratory hammer. The precast pile is installed at the bottom of the pile hole, and cement grout is filled around the precast pile to form a cement-soil pile. Alternatively, a cement mixing pile can be constructed first, and a static pressure pile driver or a non-resonant hydraulic vibratory hammer can be used to press the connected lattice column and the precast pile together into the cement mixing pile to form a cement-soil pile surrounding the precast pile. At the junction of the precast pile and the lattice column, concrete wrapped around the reinforcing cage connector is poured to form a rigid enlarged connector. This solves the problems of high noise and severe environmental pollution in existing column pile construction methods, and improves the shear and torsional resistance at the connection nodes, significantly increasing the bearing capacity of the column pile, saving manufacturing costs, and improving construction efficiency.

[0028] 2. Technical Solution

[0029] To achieve the above objectives, the technical solution provided by the present invention is as follows:

[0030] This invention discloses a YCMG method composite precast pile column, comprising a precast pile, a lattice column, a cement-soil pile, and a rigid enlarged body connector. The precast pile is disposed within a pile hole, and the top of the precast pile is connected to the lattice column. The cement-soil pile fills the space between the precast pile and the pile hole. The rigid enlarged body connector is located at the junction of the precast pile and the lattice column. Wherein:

[0031] The pile hole is formed by pressing an outer casing with a discardable pile tip into the soil using a static pressure pile driver or a non-resonance hydraulic vibratory hammer, or by mixing the soil using cement mixing pile construction machinery; the precast pile is installed to the bottom of the pile hole.

[0032] The cement-soil pile is formed by filling the voids around the precast pile with cement grout and solidifying, or by solidifying a cement mixing pile, and the top of the cement-soil pile reaches near the junction of the precast pile and the lattice column.

[0033] The rigid enlarged body connector includes a steel cage connector and a concrete enlarged body. The steel cage connector is sleeved at the junction of the precast pile and the lattice column, and the concrete enlarged body is poured and wrapped around the steel cage connector and the junction of the precast pile and the lattice column.

[0034] Furthermore, the outer casing is pulled out after the cement-soil pile and the concrete enlargement have initially set, and cement-soil is poured into the pores created after the outer casing is pulled out to form a cement-soil outer ring.

[0035] Furthermore, the precast pile is a pipe pile or a square pile, and the top of the precast pile is mechanically or welded to the lattice column.

[0036] Furthermore, the steel cage connector includes an end plate and a steel cage body. The end plate is located at the lower end of the steel cage body, and the concrete enlargement is formed by pouring concrete from bottom to top onto the upper part of the end plate through a guide pipe.

[0037] Furthermore, the precast pile is formed by connecting several precast short piles together vertically, and adjacent lattice columns are connected to each other through intermediate connectors.

[0038] Furthermore, the intermediate connector is a welded steel plate assembly, with plug-in joints at both the upper and lower ends for interlocking with the end angle steel of the corresponding lattice column. The plug-in joints are fixed to each other by bolts.

[0039] Furthermore, the lattice column is also provided with detachable baffles around its perimeter, and the baffles are provided with hooks that can be hung on the connecting plates of the lattice column.

[0040] The present invention discloses a construction method for a YCMG method composite precast pile column, comprising the following steps:

[0041] S1. Use a total station to locate the pile position, and use a static pressure pile driver or a non-resonance hydraulic vibratory hammer to press the outer casing with the discardable pile tip into the soil to form a pile hole in the soil; if hard soil layer is encountered, use a long spiral drill to drill the hole or use a high-pressure water jet on the discardable pile tip to cut and break the soil.

[0042] S2. Hoist the precast pile into the pile hole and fix it until it reaches the set elevation;

[0043] S3. Lift the lattice column and the steel cage connector, connect and fix the lattice column to the top of the precast pile, position the steel cage connector at the junction of the lattice column and the precast pile, and use the lifting bar to fix the pile hole opening.

[0044] S4. Use grouting pipes to perform cement-soil grouting from the bottom of the precast pile, grouting from bottom to top until reaching the bottom of the steel cage connector;

[0045] S5. Using a conduit, concrete is poured from the bottom up from the bottom of the steel cage connector until the top of the steel cage connector is reached, so that the precast pile and the lattice column are connected into a rigid enlarged body connector by the steel cage connector wrapped around it.

[0046] S6. After the cement soil and concrete have initially set, use a static pressure pile driver or a non-resonance hydraulic vibratory hammer to pull out the outer casing. After pulling out the outer casing, grout is injected into the gaps left by the outer casing to fill it with cement soil, forming an outer layer of cement soil.

[0047] Furthermore, the outer casing is composed of several casing pipe sections connected together, with adjacent casing pipe sections connected by a casing connection assembly. The discardable pile tip is installed at the lower end of the first casing pipe section. The casing pipe section is a double-walled steel casing. During construction, the first casing pipe section is first centered and pressed into the soil. Then, the next casing pipe section is lifted and connected to the previous casing pipe section through the casing connection assembly. The process continues until the designed pile top elevation is reached.

[0048] The cylindrical connecting assembly includes a male connector, a male connector gasket, a pin, a female connector, and a female connector gasket. The male and female connectors are respectively fixedly installed at the ends of two adjacent sections of the protective cylinder fitting. The male connector can be axially inserted into the female connector. The outer periphery of both the male and female connectors is provided with several corresponding connection holes. The male connector gasket is fixed in the corresponding connection hole of the male connector, and the female connector gasket is fixed in the corresponding connection hole of the female connector. After the male and female connectors are inserted, the positions of the male connector gasket and the female connector gasket correspond one-to-one, and the pin is correspondingly installed in the pin holes of the male connector gasket and the female connector gasket.

[0049] The present invention discloses a construction method for a YCMG method composite precast pile column, comprising the following steps:

[0050] S1. Use a total station to locate the pile position, and use cement mixing pile construction machinery to make cement mixing piles in the soil to achieve the designed pile depth requirements.

[0051] S2. Hoist the precast pile into the cement mixing pile;

[0052] S3. Lift the lattice column and the steel cage connector, connect and fix the top of the lattice column to the precast pile, fix the steel cage connector at the junction of the lattice column and the precast pile, and use a static pressure pile driver or a non-resonance hydraulic vibratory hammer to press the connected lattice column and the precast pile into the cement mixing pile together until the set elevation is reached.

[0053] S4. Use grouting pipes to perform cement-soil grouting from the bottom of the precast pile, grouting from bottom to top until reaching the bottom of the steel cage connector;

[0054] S5. Using a conduit, concrete is poured from the bottom up through the bottom of the steel cage connector until the top of the steel cage connector is reached, so that the precast pile and the lattice column are connected into a rigid enlarged body connector by the steel cage connector surrounding it.

[0055] 3. Beneficial effects

[0056] Compared with existing known technologies, the technical solution provided by this invention has the following significant advantages:

[0057] (1) The present invention relates to a YCMG method composite precast pile and its construction method. The column pile includes a precast pile, a lattice column, a cement-soil pile, and a rigid enlarged body connector. The pile hole is formed by pressing an outer casing with a discardable pile tip into the soil using a static pressure pile driver or a non-resonant hydraulic vibratory hammer. The precast pile is installed to the bottom of the pile hole, and cement grout is filled around the precast pile to form a cement-soil pile. Alternatively, a cement mixing pile can be constructed first, and the connected lattice column and precast pile can be pressed together into the cement mixing pile using a static pressure pile driver or a non-resonant hydraulic vibratory hammer to form a cement-soil pile surrounding the precast pile. The construction noise is low, and no excavation is required. It uses mud, making it environmentally friendly; and at the junction of precast piles and lattice columns, concrete wrapped around the reinforcing cage connector is poured to form a rigid enlarged connector, which solves the problem of poor shear resistance at the connection node and greatly improves the bearing capacity of the column pile; compared with existing column piles and their manufacturing methods, the construction method is simple, the construction efficiency is increased by 200% to 300%, the quality and safety at the junction of precast piles and lattice columns are reliably guaranteed, the bearing capacity of the column pile foundation is greatly improved by 10% to 50%, green and pollution-free construction is achieved, construction costs are greatly reduced, and there are significant economic and social benefits;

[0058] (2) The YCMG method composite precast pile of the present invention and its construction method, wherein the outer casing is pulled out after the cement-soil pile and the concrete enlarged body have initially set, and cement-soil is poured into the pores generated after the outer casing is pulled out to form a cement-soil outer ring, which greatly increases the frictional resistance between the pile and the soil on the side of the pile, thereby effectively improving the bearing capacity of the pile; and the outer casing is used as the pile hole wall, so there is no collapse of the hole wall or necking and other quality problems.

[0059] (3) The YCMG method composite precast pile of the present invention is a column pile and its construction method. The precast pile is a pipe pile or a square pile. The top of the precast pile is mechanically connected or welded to the lattice column. The precast pipe pile and square pile have high production efficiency and low cost, and have good bearing capacity, shear resistance and impact resistance. The composite use of precast piles also greatly improves the construction efficiency of column piles.

[0060] (4) The present invention provides a YCMG method composite precast pile column and its construction method, wherein the precast pile has an enlarged head, which further improves the bearing capacity of the column pile.

[0061] (5) The YCMG method composite precast pile of the present invention and its construction method, wherein the steel cage connector includes an end plate and a steel cage body. The end plate can improve the compressive bearing capacity, and the steel cage body can improve the shear and torsional resistance, making the rigid enlarged body connector less prone to instability and failure.

[0062] (6) The present invention provides a YCMG method composite precast pile column and its construction method. The precast pile is composed of several precast short piles connected vertically, which can meet the column pile production requirements of different designs. Adjacent lattice columns are connected to each other through intermediate connectors. The intermediate connectors can be set at the bottom slab and floor slab of each floor to facilitate the pouring of reinforced concrete of the bottom slab and floor slab. The intermediate connector is a steel plate welded part. At the upper and lower ends of the intermediate connector, there are plug joints for plugging and matching with the end angle steel of the corresponding lattice column. The intermediate connector has a simple structure, is easy to manufacture, and is convenient and quick to connect.

[0063] (7) The YCMG method composite precast pile of the present invention and its construction method are provided with a detachable baffle around the grid column. The baffle is provided with hooks that can be hung on the connecting plate of the grid column. The baffle can block the holes on the side wall of the grid column, which facilitates the hoisting of the grid column in the pile hole and the installation of the steel cage connector. Attached Figure Description

[0064] Figure 1 This is a schematic diagram of the pile formation state of a YCMG method composite precast pile according to the present invention.

[0065] Figure 2 This is a schematic diagram of the main connection structure of the column pile using pipe piles as precast piles in this invention;

[0066] Figure 3 This is a schematic diagram of the main disassembled structure of the column pile using pipe piles as precast piles in this invention;

[0067] Figure 4 This is a structural schematic diagram of the steel cage connector in this invention;

[0068] Figure 5 This is a schematic diagram of the main connection structure of the column pile using square piles as precast piles in this invention;

[0069] Figure 6 This is a schematic diagram of the main disassembled structure of the column pile using square piles as precast piles in this invention;

[0070] Figure 7 This is a schematic diagram of the installation structure of the baffle on the lattice column in this invention;

[0071] Figure 8 This is a schematic diagram of the overall structure of the outer casing in this invention;

[0072] Figure 9 This is a schematic diagram of the disassembled structure of the outer casing in this invention;

[0073] Figure 10 This is a schematic diagram of the outer casing pressing hole step in the column pile construction method of the present invention;

[0074] Figure 11 This is a schematic diagram of the precast pile fixing steps in the column pile construction method of the present invention;

[0075] Figure 12 This is a schematic diagram illustrating the installation steps of the lattice column and the steel cage connector in the column pile construction method of the present invention.

[0076] Figure 13 This is a schematic diagram of the steps in the column pile construction method of the present invention to form a cement-soil pile by pouring cement-soil.

[0077] Figure 14 This is a schematic diagram of the steps in the column pile construction method of the present invention, which involves pouring concrete enlargement and cement-soil outer ring.

[0078] Figure 15 This is a schematic diagram of the structural state of a simplified column pile using the cement mixing pile process in this invention.

[0079] Explanation of the labels in the diagram:

[0080] 1. Precast pile; 1-1. Enlarged head; 2. Lattice column; 2A. Baffle; 2A-1. Hook; 2-1. End angle steel; 3. Intermediate connector; 3-1. Plug-in joint; 4. Cement-soil pile; 5. Reinforcing cage connector; 5-1. End plate; 5-2. Reinforcing cage body; 6. Concrete enlarged body; 7. Cement-soil outer ring; 8. Grouting pipe; 9. Outer casing; 9-1. Casing fittings; 9-2. Casing connection assembly; 9-2-1. Male connector; 9-2-2. Male connector gasket; 9-2-3. Pin; 9-2-4. Female connector; 9-2-5. Female connector gasket; 9-3. Disposable pile tip; 10. Connecting bolt. Detailed Implementation

[0081] To further understand the content of this invention, a detailed description of the invention will be provided in conjunction with the accompanying drawings.

[0082] This invention discloses a YCMG method composite precast pile and its construction method. The method involves using a static pressure pile driver or a non-resonant hydraulic vibratory hammer to press an outer casing with a discardable pile tip into the soil to form a pile hole. Alternatively, a cement mixing pile can be constructed first, and then a static pressure pile driver or a non-resonant hydraulic vibratory hammer can be used to press the connected lattice column and precast pile together into the cement mixing pile. This solves the problems of high noise and severe environmental pollution associated with existing column pile construction methods. Furthermore, the precast pile is used in conjunction with the column pile, with cement grout filling the outer periphery of the precast pile to form a cement-soil pile. At the junction of the precast pile and the lattice column, concrete encasing a reinforcing cage connector is poured to form a rigid enlarged connector, solving the problems of poor bearing capacity and poor torsional and shear resistance at the junction of existing column piles. For ease of understanding and description, the "YCMG method" is specifically used to illustrate the technological characteristics of the column piles in this invention. In the "YCMG method," "Y" means: A casing with a pile tip is pressed into the soil using static pressure (e.g., a static pressure pile driver or a non-resonant hydraulic vibratory hammer) to form a pile hole; or cement mixing piles are constructed in the soil using cement mixing pile construction machinery, and the connected lattice column and precast pile are pressed together into the cement mixing pile using a static pressure pile driver or a non-resonant hydraulic vibratory hammer. "C" means: Precast piles are used in combination within the pile hole. These precast piles are installed at the bottom of the pile hole. The precast piles can be pipe piles or square piles, and enlarged heads can be installed on them. "M" means: After the precast piles (pipe piles or square piles) are installed, cement grouting is performed, filling the gaps around the precast piles from bottom to top until reaching the junction of the precast pile and the upper lattice column, forming a ring of cement-soil piles. The meaning of “G” is: a rigid enlarged body connector is set at the junction of the precast pile and the lattice column. The rigid enlarged body connector includes a steel cage connector and a concrete enlarged body. The steel cage connector is fitted at the junction of the precast pile and the lattice column. Concrete is poured from the bottom of the steel cage connector from bottom to top, connecting the precast pile and the lattice column into a rigid enlarged body connector by the steel cage connector wrapped around it.

[0083] Figures 1 to 7This invention illustrates the pile formation state and main structure of the YCMG composite precast pile of the present invention. The pile mainly consists of a precast pile 1, a lattice column 2, a cement-soil pile 4, and a rigid enlarged body connector. Structurally, the precast pile 1 is placed inside the pile hole, with its top connected to the lattice column 2. The cement-soil pile 4 fills the space between the precast pile 1 and the pile hole. The rigid enlarged body connector is located at the junction of the precast pile 1 and the lattice column 2. In terms of construction technology, the pile hole is formed by pressing an outer casing 9 with a discardable pile tip 9-3 into the soil using a static pressure pile driver or a non-resonant hydraulic vibratory hammer. The precast pile 1 is installed to the bottom of the pile hole. The cement-soil pile 4 is formed by filling the voids around the precast pile 1 with cement grout and solidifying it, with the top of the cement-soil pile 4 reaching near the junction of the precast pile 1 and the lattice column 2. Another feasible process is to first use cement mixing pile construction machinery to create cement mixing piles in the soil. The pile holes are formed by mixing the soil in the cement mixing pile construction machinery. Then, a static pressure pile driver or a non-resonant hydraulic vibratory hammer is used to press the connected lattice column and precast pile together into the cement mixing pile. The cement-soil pile 4 is formed by the solidification of the cement mixing pile or by pouring cement and soil into the cement mixing pile. The rigid enlarged body connector includes a steel cage connector 5 and a concrete enlarged body 6. The steel cage connector 5 is fitted at the junction of the precast pile 1 and the lattice column 2. The concrete enlarged body 6 is poured and wrapped around the steel cage connector 5 and the junction of the precast pile 1 and the lattice column 2. Figures 1 to 3 The diagram shows a structural form using pipe piles as precast piles. Figures 5 to 6 The diagram shows a structural form using square piles as precast piles. Figure 7 A structure of a steel cage connector 5 is given, which includes an end plate 5-1 and a steel cage body 5-2, with the end plate 5-1 located at the lower end of the steel cage body 5-2.

[0084] Figure 8 and Figure 9The invention illustrates an auxiliary construction tool for pile hole formation, namely an outer casing 9. The outer casing 9 is composed of several casing pipe sections 9-1 connected together. Adjacent casing pipe sections 9-1 are connected by a casing connecting assembly 9-2. A discardable pile tip 9-3 is installed at the lower end of the first casing pipe section 9-1. The casing connecting assembly 9-2 includes a male connector 9-2-1, a male connector gasket 9-2-2, a pin 9-2-3, a female connector 9-2-4, and a female connector gasket 9-2-5. The male connector 9-2-1 and the female connector 9-2-4 are respectively fixedly installed at the ends of two adjacent casing pipe sections 9-1. The male connector 9-2-1 can be axially inserted into the female connector 9-2-4. The outer periphery of both the male connector 9-2-1 and the female connector 9-2-4 is provided with several connecting... The male connector gasket 9-2-2 is fixed in the corresponding connection hole of the male connector 9-2-1, and the female connector gasket 9-2-5 is fixed in the corresponding connection hole of the female connector 9-2-4. After the male connector 9-2-1 and the female connector 9-2-4 are inserted, the positions of the male connector gasket 9-2-2 and the female connector gasket 9-2-5 correspond one-to-one, and the pin 9-2-3 is correspondingly installed in the pin holes of the male connector gasket 9-2-2 and the female connector gasket 9-2-5. The outer casing 9 with the discardable pile tip 9-3 is pressed into the soil by static pressure to form a pile hole in the soil. After the outer casing 9 is pulled out, the discardable pile tip 9-3 remains at the bottom of the column pile.

[0085] Figures 10 to 14 The diagram illustrates the construction status of each step in the column pile construction method. The specific construction method includes the following steps:

[0086] S1. Use a total station to locate the pile position, and use a static pressure pile driver or a non-resonance hydraulic vibratory hammer to press the outer casing 9 with the discardable pile tip 9-3 into the soil to form a pile hole in the soil; if a hard soil layer is encountered, use a long spiral drill to drill the hole or use a high-pressure water jet on the discardable pile tip 9-3 to cut and break the soil.

[0087] S2. Hoist the precast pile 1 into the pile hole and fix it until it reaches the set elevation;

[0088] S3. Lift the lattice column 2 and the steel cage connector 5, connect and fix the top of the lattice column 2 to the precast pile 1, position the steel cage connector 5 at the junction of the lattice column 2 and the precast pile 1, and use the lifting bar to fix the pile hole opening.

[0089] S4. Use grouting pipe 8 to perform cement-soil grouting from the bottom of precast pile 1, and grout from bottom to top until the bottom of the steel cage connector 5 is reached.

[0090] S5. Using a conduit, concrete is poured from the bottom up from the bottom of the steel cage connector 5 until the top of the steel cage connector 5, so that the precast pile 1 and the lattice column 2 are connected into a rigid enlarged body connector by the steel cage connector 5 wrapped around it.

[0091] S6. After the cement soil and concrete have initially set, use a static pressure pile driver or a non-resonance hydraulic vibratory hammer to pull out the outer casing 9. After pulling out the outer casing 9, grout is injected into the pores after the outer casing 9 is pulled out to fill the cement soil, forming the cement soil outer ring 7.

[0092] Accordingly, when using the cement mixing pile technology, the construction method includes the following steps:

[0093] S1. Use a total station to locate the pile position, and use cement mixing pile construction machinery to make cement mixing piles in the soil to achieve the designed pile depth requirements.

[0094] S2. The precast pile 1 is hoisted into the cement mixing pile. At this time, the cement mixing pile is still in a soft state.

[0095] S3. Lift the lattice column 2 and the steel cage connector 5, connect and fix the top of the lattice column 2 to the precast pile 1, fix the steel cage connector 5 at the junction of the lattice column 2 and the precast pile 1, and use a static pressure pile driver or a non-resonance hydraulic vibratory hammer to press the connected lattice column 2 and the precast pile 1 into the cement mixing pile until the set elevation is reached.

[0096] S4. When the cement mixing pile has not reached the above-mentioned cement-soil pile 4 elevation, use the grouting pipe 8 to perform cement-soil grouting from the bottom of the precast pile 1, and grout from bottom to top until it reaches the lower part of the steel cage connector 5.

[0097] S5. Using a conduit, concrete is poured from the bottom up from the bottom of the steel cage connector 5 until the top of the steel cage connector 5, so that the precast pile 1 and the lattice column 2 are connected into a rigid enlarged body connector by the steel cage connector 5 wrapped around it.

[0098] The YCMG composite precast pile and its construction method of the present invention solve the problems of high noise and serious environmental pollution of existing pile construction methods, and improve the shear and torsional resistance of the connection nodes, thereby greatly improving the bearing capacity of the pile, saving manufacturing costs and improving construction efficiency.

[0099] The present invention will be further described below with reference to embodiments.

[0100] [Example 1]

[0101] like Figure 1As shown in this embodiment, a YCMG method composite precast pile includes a precast pile 1, a lattice column 2, a cement-soil pile 4, and a rigid enlarged body connector. The precast pile 1 is installed in the pile hole, and the top of the precast pile 1 is connected to the lattice column 2. The cement-soil pile 4 fills the space between the precast pile 1 and the pile hole. The rigid enlarged body connector is located at the junction of the precast pile 1 and the lattice column 2. The pile hole is formed by pressing an outer casing 9 with a discardable pile tip 9-3 into the soil using a static pressure pile driver or a non-resonant hydraulic vibratory hammer. This process eliminates the need for excavation, generates no mud, solves the problem of sludge pollution, and reduces construction noise, thus minimizing noise pollution to the surrounding area. The precast pile 1 is installed to the bottom of the pile hole and positioned within it. During this process, the outer casing 9 acts as a retaining wall for the pile hole, preventing collapse or necking that could affect quality. This facilitates the construction of the precast pile 1, lattice column 2, cement-soil pile 4, and rigid enlarged body connector within the pile hole. The cement-soil pile 4 is formed by filling the voids around the precast pile 1 with cement grout and solidifying. The top of the cement-soil pile 4 reaches near the junction of the precast pile 1 and the lattice column 2. Using the precast pile 1 improves the bearing capacity of the column pile, saves costs, and improves construction efficiency. The rigid enlarged body connector includes a steel cage connector 5 and a concrete enlarged body 6. The steel cage connector 5 is fitted at the junction of the precast pile 1 and the lattice column 2. The concrete enlarged body 6 is poured and wrapped around the steel cage connector 5 and the junction of the precast pile 1 and the lattice column 2, thus forming the rigid enlarged body connector. The rigid enlarged body connector improves the shear and torsional resistance at the connection point of the precast pile 1 and the lattice column 2, avoiding the problem of column pile instability and failure.

[0102] In this embodiment, the outer casing 9 is pulled out after the cement-soil pile 4 and the concrete enlargement 6 have initially set. Cement-soil is then poured into the pores created after the outer casing 9 is pulled out, forming a cement-soil outer ring 7. This significantly increases the frictional resistance between the pile and the soil around the pile, thereby effectively improving the pile's bearing capacity. When the outer casing 9 is pulled out, the discardable pile tip 9-3 detaches from the outer casing 9, becoming part of the column pile. The discardable pile tip 9-3 has a conical structure, serving as a guide during the drilling process, facilitating the insertion of the outer casing 9 into the soil. The discardable pile tip 9-3 is also equipped with a high-pressure water jet. When encountering hard soil layers, the high-pressure water jet is activated to cut and break up the soil, assisting in pile driving and improving drilling efficiency. The nozzle of the high-pressure water jet is installed on the discardable pile tip 9-3. The high-pressure fluid equipment can be detachably connected to the nozzle via a pipeline, and can be removed after the outer casing 9 has been drilled. The discardable pile tip 9-3 and the outer casing 9 can be connected by an axial insertion structure. When the outer casing 9 is pulled outward, the discardable pile tip 9-3 can naturally separate from the outer casing 9.

[0103] like Figure 2 and Figure 3As shown, in this embodiment, the precast pile 1 is a pipe pile, and the top of the precast pile 1 is mechanically or welded to the lattice column 2. Precast pipe piles are efficient and low-cost to manufacture, and have good bearing capacity, shear resistance, and impact resistance. The combined use of precast piles also greatly improves the construction efficiency of the column piles. The precast pile 1 also has an enlarged head 1-1, which further improves the bearing capacity of the column pile. Of course, the precast pile 1 can also be other precast pile types such as square piles.

[0104] like Figure 4 As shown, the aforementioned reinforcing cage connector 5 includes an end plate 5-1 and a reinforcing cage body 5-2. The end plate 5-1 is located at the lower end of the reinforcing cage body 5-2, and the two can be welded together. The concrete expansion body 6 is formed by pouring concrete from bottom to top on the upper part of the end plate 5-1 through a guide pipe. As the skeleton of the rigid expansion body connector, the end plate 5-1 can prevent the reinforcing cage connector 5 from sinking, greatly improving the structural strength at the connection position between the precast pile 1 and the lattice column 2, improving the torsional and shear resistance, and making the rigid expansion body connector less prone to instability and failure. The reinforcing cage body 5-2 can be composed of main bars, stirrups, and spiral bars. The main bars are welded to the stirrups to fix them. After the main bars are welded, spiral bars are welded to them to form a cage-like structure.

[0105] The design height of precast pile 1 varies depending on different design requirements. To meet the design requirements of different column piles, in this embodiment, precast pile 1 is composed of several precast short piles connected vertically. Adjacent precast short piles can be mechanically or welded together. The height requirements of precast pile 1 can be met by connecting multiple precast short piles. The structure of lattice column 2 is similar to that of existing technology, mainly composed of column angle steel and several connecting plates welded together, and can be prefabricated in the factory. Adjacent lattice columns 2 are connected to each other by intermediate connectors 3. Intermediate connectors 3 can be set at the bottom slab and floor slab of each floor, which facilitates the pouring of reinforced concrete for the bottom slab and floor slab, and avoids the problem of difficult reinforcement insertion and construction difficulties caused by the cement and soil mixed at the junction of lattice column 2 and bottom slab / floor slab. (Refer to...) Figure 3 As shown, the aforementioned intermediate connector 3 is a welded steel plate assembly. At both the upper and lower ends of the intermediate connector 3 are plug-in joints 3-1 for interlocking with the end angle steel 2-1 of the corresponding lattice column 2. The plug-in joints 3-1 are fixed together with bolts. The plug-in joints 3-1 have a rectangular frame structure, and the upper and lower plug-in joints 3-1 can be connected by a cross-shaped connecting plate. The plug-in joints 3-1 can be inserted into the rectangular ports formed by the four end angle steels 2-1 of the corresponding lattice column 2, and then fixed with bolts. Using the aforementioned intermediate connector 3 results in a simple structure, convenient manufacturing, and quick and easy connection operation.

[0106] In addition, such as Figure 7As shown, a detachable baffle 2A is provided around the lattice column 2. The baffle 2A is equipped with hooks 2A-1 that can be hung on the connecting plate of the lattice column 2. The baffle 2A can block the holes on the side wall of the lattice column 2, which facilitates the hoisting of the lattice column 2 in the pile hole and the installation of the steel cage connector 5.

[0107] This embodiment also relates to a construction method for the column pile of a YCMG composite precast pile. Combined with... Figures 10 to 14 As shown, the construction method includes the following steps:

[0108] S1. Using a total station to locate the pile position, a pile driver with a static or non-resonance hydraulic vibratory hammer is used to press the outer casing 9, equipped with a discardable pile tip 9-3, into the soil, forming a pile hole in the soil (e.g., ...). Figure 10 (As shown); if encountering hard soil layers, a long spiral drill bit is used for pre-drilling or a high-pressure water jet on the discardable pile tip 9-3 is used to cut and break the soil. Specifically, the outer casing 9 is composed of several casing pipe sections 9-1 connected together. Adjacent casing pipe sections 9-1 are connected by a casing connecting assembly 9-2. The discardable pile tip 9-3 is installed at the lower end of the first casing pipe section 9-1. The casing pipe section 9-1 is a double-walled steel casing, which can be composed of an outer wall pipe, an inner wall pipe, and a sandwich support. The outer wall pipe is sleeved on the outside of the inner wall pipe, forming a sandwich between the outer wall pipe and the inner wall pipe. A sandwich support is provided in the sandwich. The outer wall pipe and the inner wall pipe are connected as a whole by the sandwich support, resulting in high structural strength. The sandwich support can be a support ring spaced along the axial direction or a honeycomb support plate located in the sandwich, which greatly enhances the structural strength of the outer casing 9 and enables it to withstand greater pressure. During construction, the first section of the casing pipe fitting 9-1 is first aligned and pressed into the soil. Then, the next section of the casing pipe fitting 9-1 is lifted and connected to the previous section via the casing connection assembly 9-2. This process continues until the designed pile top elevation is reached. (Refer to...) Figure 9As shown, the aforementioned cylindrical connecting assembly 9-2 includes a male connector 9-2-1, a male connector gasket 9-2-2, a pin 9-2-3, a female connector 9-2-4, and a female connector gasket 9-2-5. The male connector 9-2-1 and female connector 9-2-4 are respectively fixedly installed at the ends of two adjacent sections of the protective sleeve fitting 9-1. The male connector 9-2-1 and female connector 9-2-4 can be welded to their corresponding protective sleeve fittings 9-1. The male connector 9-2-1 can be axially inserted into the female connector 9-2-4. Both the male connector 9-2-1 and female connector 9-2-4 have several corresponding connecting holes on their outer circumferences. The male connector gasket 9-2-5... -2 is fixed in the corresponding connection hole of the male connector 9-2-1, and the female connector gasket 9-2-5 is fixed in the corresponding connection hole of the female connector 9-2-4. The male connector gasket 9-2-2 and the female connector gasket 9-2-5 can also be welded and fixed in the corresponding connection holes. The male connector gasket 9-2-2 and the female connector gasket 9-2-5 are provided with pin holes. After the male connector 9-2-1 and the female connector 9-2-4 are inserted, the positions of the male connector gasket 9-2-2 and the female connector gasket 9-2-5 correspond one-to-one, and the pin 9-2-3 is correspondingly installed in the pin holes of the male connector gasket 9-2-2 and the female connector gasket 9-2-5. The pin 9-2-3 can be inserted into the pin hole by tapping to prevent it from falling out. Alternatively, an internal thread can be provided in the pin hole of the female connector gasket 9-2-5. The front section of the pin 9-2-3 has a necked design, and the rear section has an external thread. The threaded connection between the pin 9-2-3 and the female connector gasket 9-2-5 prevents loosening. The front section of the pin 9-2-3 is inserted into the pin hole of the male connector gasket 9-2-2 to achieve connection. The above-mentioned cylinder connecting assembly 9-2 adopts a male-female mating connector design, using the pin 9-2-3 for locking connection. The structure is simple, the connection is convenient, and the connection is firm and reliable.

[0109] S2. Hoist the precast pile 1 into the pile hole and fix it until it reaches the set elevation. The state of the precast pile 1 in the pile hole is as follows: Figure 11 As shown. In specific operation, a crane is used to lift the first precast short pile into the pile hole and fix it. The next precast short pile is then lifted into the pile hole and connected to the upper end of the previous precast short pile through mechanical or welding connection. The above installation operation of the precast short pile is repeated according to the design elevation until the elevation of precast pile 1 is reached.

[0110] S3. Lift the lattice column 2 and the reinforcing cage connector 5, connect and fix the lattice column 2 to the top of the precast pile 1, position the reinforcing cage connector 5 at the junction of the lattice column 2 and the precast pile 1, and fix the pile hole opening using lifting bars. The state of the lattice column 2 and the reinforcing cage connector 5 inside the pile hole is as follows. Figure 12As shown, the lattice column 2 is mechanically or welded to the precast pile 1, and the reinforcing cage connector 5 can be fixed by means of lifting bars, etc. At the same time, steel pipes or small lattice columns with reinforcing cages can be inserted into the precast pipe piles to further improve the structural strength of the precast pipe piles.

[0111] S4. The grouting pipe 8 is lowered to the bottom of the precast pile 1. Cement-soil grouting is then performed from the bottom of the precast pile 1 using the grouting pipe 8, proceeding from bottom to top until the lower part of the reinforcing cage connector 5 is reached, forming... Figure 13 Cement-soil pile 4 in the state shown.

[0112] S5. Using a conduit, concrete is poured from the bottom up through the lower part of the reinforcing cage connector 5 (i.e., the upper part of the end plate 5-1) until the top of the reinforcing cage connector 5, so that the precast pile 1 and the lattice column 2 are connected into a rigid enlarged body connector by the reinforcing cage connector 5 surrounding it. Figure 14 As shown, by forming a rigid enlarged body connector at the junction of the precast pile 1 and the lattice column 2, the structural strength of the junction is greatly improved.

[0113] S6. After the initial setting of the cement-soil and concrete, the outer casing 9 is pulled out using a static pressure pile driver or a non-resonant hydraulic vibratory hammer. After pulling out the outer casing 9, cement-soil is injected into the pores left by the outer casing 9 to form a cement-soil outer ring 7, ultimately presenting... Figure 14 The outer casing 9 should be pulled out slowly and evenly to avoid excessive speed, which could affect the quality of the concrete.

[0114] [Example 2]

[0115] The YCMG method composite precast pile column and its construction method in this embodiment are similar in basic structure and principle to those in Embodiment 1, except that:

[0116] In this embodiment, the precast pile 1 is preferably a square pile. The pile hole is formed by mixing the soil in the cement mixing pile construction machinery. The precast square pile is driven into the cement mixing pile, and the cement-soil pile 4 is formed by the solidification of the cement mixing pile. Figure 5 and Figure 6 As shown, a connecting portion is pre-reserved at the top of the precast square pile. This connecting portion can be four angle steels pre-embedded at the top of the square pile. When connected to the lattice column 2, the four angle steels at the top of the square pile and the end angle steel 2-1 at the bottom of the lattice column 2 are interlocked and fixed with bolts. Compared with the precast pipe pile in Example 1, the square pile has better bearing capacity and shear and impact resistance, thus the overall bearing capacity of the manufactured column pile is also better. Correspondingly, the center hole of the end plate 5-1 of the reinforcing cage connector 5 can also be a square hole adapted to the square pile.

[0117] This embodiment describes a construction method for a YCMG method composite precast pile column, which includes the following steps:

[0118] S1. A total station is used to locate the pile positions. Cement mixing piles are then constructed in the soil using cement mixing pile construction machinery, achieving the designed pile depth. The cement mixing pile construction machinery is existing equipment, and cement mixing piles can be produced using existing cement mixing pile construction techniques. Cement mixing pile construction does not generate sludge, reducing sludge pollution.

[0119] S2. When the cement mixing pile is in a soft and flowable state (uncured), the precast pile 1 is hoisted into the cement mixing pile. The top of the precast pile 1 is reserved with a connection part for connecting the lattice column 2. For example, four angle steels are set at the top of the precast square pile to facilitate mechanical connection or welding with the lattice column 2.

[0120] S3. Lift the lattice column 2 and the reinforcing cage connector 5, connect and fix the top of the lattice column 2 to the precast pile 1, and fix the reinforcing cage connector 5 at the junction of the lattice column 2 and the precast pile 1. Use a static pressure pile driver or a non-resonance hydraulic vibratory hammer to press the connected lattice column 2 and the precast pile 1 together into the cement mixing pile until the set elevation is reached. At this time, the lattice column 2 can be used as the force-applying column for the static pressure pile driver or the non-resonance hydraulic vibratory hammer to drive the precast pile 1 into the cement mixing pile. This construction process has low noise and is simple and convenient. When pressing the precast pile 1, a baffle 2A can also be set on the corresponding lattice column 2. The baffle 2A can reduce the resistance of the lattice column 2 entering the cement mixing pile.

[0121] S4. After the precast pile 1 is driven in, if the cement mixing pile still does not reach the elevation of the cement-soil pile 4 mentioned above, the cement-soil is grouted from the bottom of the precast pile 1 using the grouting pipe 8, and the grouting is carried out from bottom to top until it reaches the lower part of the steel cage connector 5.

[0122] S5. Using a guide pipe, concrete is poured from the bottom up through the lower part of the reinforcing cage connector 5 until the top of the connector 5 is reached. This connects the precast pile 1 and the lattice column 2 into a rigid expanded body connector through the reinforcing cage connector 5 surrounding them, forming... Figure 14 The column piles are shown in the diagram. By forming a rigid enlarged connector at the junction of the precast pile 1 and the lattice column 2, the structural strength at the junction is greatly improved.

[0123] As an extension, Figure 15 This paper illustrates a simplified column pile using cement mixing pile technology. Compared to the column piles described above, the reinforcing cage connector 5 is eliminated, and the junction of the precast pile 1 and the lattice column 2 is reinforced with cement mixing piles. This method has good practical value in many column pile foundation structures, and the construction process is simpler. The specific construction method is as follows:

[0124] S1. Use a total station to locate the pile position, and use cement mixing pile construction machinery to make cement mixing piles in the soil to achieve the designed pile depth requirements.

[0125] S2. When the cement mixing pile is in a soft and flowable state (uncured), the precast pile 1 is hoisted into the cement mixing pile. The precast pile 1 is preferably a precast square pile, and its top has a pre-reserved connection part for connecting to the lattice column 2. For example, four angle steels are installed at the top of the precast square pile to facilitate mechanical connection or welding with the lattice column 2. Figure 15 The diagram shows a structure in which precast pile 1 and lattice column 2 are fixedly connected by connecting bolts 10.

[0126] S3. Lift the lattice column 2, connect and fix it to the top of the precast pile 1, and then use a static pressure pile driver or a non-resonance hydraulic vibratory hammer to press the connected lattice column 2 and precast pile 1 together into the cement mixing pile until the set elevation is reached. At this time, the lattice column 2 can be used as the force-applying column for the static pressure pile driver or non-resonance hydraulic vibratory hammer to drive the precast pile 1 into the cement mixing pile. The junction of the precast pile 1 and the lattice column 2 is also driven into the cement mixing pile, and reinforced by the outer cement-soil piles 4. After the cement mixing pile solidifies, it forms... Figure 15 The shown column pile.

[0127] This invention discloses a YCMG method composite precast pile column and its construction method. The construction noise is low, and it requires no excavation or mud, making it environmentally friendly. The precast pile is installed to the bottom of the pile hole, forming a cement-soil pile around it. At the junction of the precast pile and the lattice column, concrete wrapped around the reinforcing cage connector is poured to form a rigid enlarged connector, solving the problem of poor shear resistance at the connection node and significantly improving the bearing capacity of the column pile. Compared with existing column piles and their manufacturing methods, the construction method is simpler, construction efficiency is increased by 200%–300%, the quality and safety at the junction of the precast pile and the lattice column are reliably guaranteed, and the bearing capacity of the column pile foundation is significantly improved by 10%–50%. This achieves green and pollution-free construction, significantly reduces construction costs, and has significant economic and social benefits.

[0128] The present invention and its embodiments have been described above illustratively. This description is not restrictive, and the figures shown are only one embodiment of the present invention; the actual structure is not limited thereto. Therefore, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the spirit of the present invention, such designs should fall within the protection scope of the present invention.

Claims

1. A column pile for YCMG method composite precast piles, characterized in that: The system includes precast piles (1), lattice columns (2), cement-soil piles (4), and rigid enlarged body connectors. The precast piles (1) are installed in the pile hole, and the top of the precast piles (1) is connected to the lattice columns (2). The cement-soil piles (4) fill the space between the precast piles (1) and the pile hole. The rigid enlarged body connectors are located at the junction of the precast piles (1) and the lattice columns (2). The pile hole is formed by pressing an outer casing (9) with a discardable pile tip (9-3) into the soil using a static pressure pile driver or a non-resonance hydraulic vibratory hammer, or by mixing the soil using cement mixing pile construction machinery; the precast pile (1) is installed to the bottom of the pile hole; The cement-soil pile (4) is formed by filling the voids around the precast pile (1) with cement grout and solidifying, or by solidifying the cement mixing pile, and the top of the cement-soil pile (4) reaches near the junction of the precast pile (1) and the lattice column (2). The rigid enlarged body connector includes a steel cage connector (5) and a concrete enlarged body (6). The steel cage connector (5) is sleeved at the junction of the precast pile (1) and the lattice column (2). The concrete enlarged body (6) is poured and wrapped around the steel cage connector (5) and the junction of the precast pile (1) and the lattice column (2).

2. The column pile of the YCMG method composite precast pile according to claim 1, characterized in that: The outer casing (9) is pulled out after the cement-soil pile (4) and the concrete enlargement (6) have initially set, and cement-soil is poured into the pores generated after the outer casing (9) is pulled out to form a cement-soil outer ring layer (7).

3. The column pile of the YCMG method composite precast pile according to claim 1 or 2, characterized in that: The precast pile (1) is a pipe pile or a square pile, and the top of the precast pile (1) is mechanically connected or welded to the lattice column (2).

4. The column pile of the YCMG method composite precast pile according to claim 1, characterized in that: The steel cage connector (5) includes an end plate (5-1) and a steel cage body (5-2). The end plate (5-1) is located at the lower end of the steel cage body (5-2). The concrete enlargement (6) is formed by pouring concrete from bottom to top on the upper part of the end plate (5-1) through a guide pipe.

5. The column pile of the YCMG method composite precast pile according to claim 1, characterized in that: The precast pile (1) is formed by connecting several precast short piles together vertically, and the adjacent lattice columns (2) are connected to each other through intermediate connectors (3).

6. The column pile of the YCMG method composite precast pile according to claim 5, characterized in that: The intermediate connector (3) is a welded steel plate assembly. At the upper and lower ends of the intermediate connector (3), there are plug-in connectors (3-1) for plugging and engaging with the end angle steel (2-1) of the corresponding lattice column (2). The plug-in connectors (3-1) are fixed to each other by bolts.

7. The column pile of the YCMG method composite precast pile according to claim 1, characterized in that: The lattice column (2) is also provided with a detachable baffle (2A) around its perimeter, and the baffle (2A) is provided with a hook (2A-1) that can be hung on the connecting plate of the lattice column (2).

8. A construction method for the column pile of the YCMG composite precast pile according to any one of claims 1 to 7, characterized in that, Includes the following steps: S1. Use a total station to locate the pile position, and use a static pressure pile driver or a non-resonance hydraulic vibratory hammer to press the outer casing (9) with the discardable pile tip (9-3) into the soil to form a pile hole in the soil. If a hard soil layer is encountered, use a long spiral drill to drill the hole or use a high-pressure water jet on the discardable pile tip (9-3) to cut and break the soil. S2. Hoist the precast pile (1) into the pile hole and fix it to the set elevation; S3. Lift the lattice column (2) and the steel cage connector (5), connect and fix the top of the lattice column (2) and the precast pile (1), position the steel cage connector (5) at the junction of the lattice column (2) and the precast pile (1), and fix the pile hole opening with the lifting bar. S4. Use the grouting pipe (8) to perform cement-soil grouting from the bottom of the precast pile (1), and grout from bottom to top until the bottom of the steel cage connector (5) is reached. S5. Using a conduit, concrete is poured from the bottom up from the bottom of the steel cage connector (5) until the top of the steel cage connector (5), so that the precast pile (1) and the lattice column (2) are connected into a rigid enlarged body connector by the steel cage connector (5) wrapped around it. S6. After the cement soil and concrete have initially set, the outer casing (9) is pulled out using a static pressure pile driver or a non-resonance hydraulic vibratory hammer. After the outer casing (9) is pulled out, cement soil is injected into the pores after the outer casing (9) is pulled out to form an outer layer of cement soil (7).

9. The construction method for the column pile of the YCMG composite precast pile according to claim 8, characterized in that: The outer casing (9) is composed of several casing pipe sections (9-1) connected together. Adjacent casing pipe sections (9-1) are connected by a casing connection assembly (9-2). The discardable pile tip (9-3) is installed at the lower end of the first casing pipe section (9-1). The casing pipe section (9-1) is a double-walled steel casing. During construction, the first casing pipe section (9-1) is first centered and pressed into the soil. Then, the next casing pipe section (9-1) is lifted and connected to the previous casing pipe section (9-1) through the casing connection assembly (9-2). The casing is then pressed in until the designed pile top elevation is reached. The cylindrical connecting assembly (9-2) includes a male connector (9-2-1), a male connector gasket (9-2-2), a pin (9-2-3), a female connector (9-2-4), and a female connector gasket (9-2-5). The male connector (9-2-1) and the female connector (9-2-4) are respectively fixedly installed at the ends of two adjacent sections of the protective cylinder fitting (9-1). The male connector (9-2-1) can be axially inserted into the female connector (9-2-4). The outer periphery of both the male connector (9-2-1) and the female connector (9-2-4) is provided with several... The male connector gasket (9-2-2) is fixed in the corresponding connection hole of the male connector (9-2-1), and the female connector gasket (9-2-5) is fixed in the corresponding connection hole of the female connector (9-2-4). After the male connector (9-2-1) and the female connector (9-2-4) are inserted, the positions of the male connector gasket (9-2-2) and the female connector gasket (9-2-5) correspond one-to-one, and the pin (9-2-3) is correspondingly installed in the pin holes of the male connector gasket (9-2-2) and the female connector gasket (9-2-5).

10. A construction method for the column pile of the YCMG composite precast pile according to any one of claims 1 to 7, characterized in that, Includes the following steps: S1. Use a total station to locate the pile position, and use cement mixing pile construction machinery to make cement mixing piles in the soil to achieve the designed pile depth requirements. S2. The precast pile (1) is hoisted into the cement mixing pile; S3. Lift the lattice column (2) and the steel cage connector (5), connect and fix the top of the lattice column (2) and the precast pile (1), fix the steel cage connector (5) at the junction of the lattice column (2) and the precast pile (1), and use a static pressure pile driver or a non-resonance hydraulic vibratory hammer to press the connected lattice column (2) and the precast pile (1) into the cement mixing pile until the set elevation is reached. S4. Use the grouting pipe (8) to perform cement-soil grouting from the bottom of the precast pile (1), and grout from bottom to top until the bottom of the steel cage connector (5) is reached. S5. Using a conduit, concrete is poured from the bottom up from the bottom of the steel cage connector (5) until the top of the steel cage connector (5), so that the precast pile (1) and the lattice column (2) are connected into a rigid enlarged body connector by the steel cage connector (5) wrapped around it.

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