Soft foundation stiff composite pile and construction technology thereof
Through the combined structure of the limit bracket and steel pipe, the precast concrete pipe piles are ensured to be inserted vertically in the cement soil, and combined with the plastic drainage plate and vacuum tube to absorb water, the problem of the strength and friction resistance of the cement soil pile body is solved, and efficient and stable soft foundation stiff composite pile construction is achieved.
Patent Information
- Application Number
- CN202410197415.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-02-22
- Publication Date
- 2025-08-26
AI Technical Summary
The existing soft-based strong composite piles have a great influence on the strength of cement soil pile body and the degree of friction resistance of piles due to soil quality and groundwater factors. Prefabricated concrete piles are prone to deflection when pressed, and the extrusion effect leads to a greater pressure of superpore water.
The combined structure of limit brackets, steel pipes, cement soil mixing piles and precast concrete pipe piles is adopted. Through the coordination of limit brackets and steel pipes, the precast concrete pipe piles are ensured to be inserted vertically in the cement soil, and excess moisture is absorbed through the plastic drainage plates and vacuum pipes to solve the problem of ultra-pore water pressure.
The vertical insertion and pile quality of precast concrete pipe piles are achieved, which reduces energy consumption, avoids the generation of ultra-pore water pressure, and improves construction quality and efficiency.
Smart Images
Figure HDA0004710244360000011 
Figure HDA0004710244360000012 
Figure HDA0004710244360000021
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of soft foundation reinforced composite piles, and in particular relates to a soft foundation reinforced composite pile and a construction process thereof. Background Art
[0002] Deep, soft clay layers with high moisture content, high compressibility, low bearing capacity, poor permeability, and high sensitivity are widespread in my country's eastern coastal areas. Highway and railway construction projects in these areas often require reinforcement of these soft soil foundations. Composite pile foundations offer a highly reliable and cost-effective reinforcement method, and have been widely used in various construction projects.
[0003] However, the existing soft foundation reinforced composite piles have the following disadvantages: 1. The strength of the cement soil pile body and the degree of pile side friction resistance are greatly affected by factors such as soil quality and groundwater, especially when encountering silt soil, peat soil, etc., the construction quality is difficult to guarantee; 2. During the pressing process of precast concrete piles, it is difficult to ensure that they are located in the center position of the cement soil mixing pile, and they are prone to deflection during pressing, making it difficult to achieve the expected effect; 3. Driving precast piles in cement soil not only consumes a lot of energy, but also the squeezing effect causes a large excess pore water pressure in the soft clay around the pile, which is not easy to dissipate. Therefore, there is an urgent need for a soft foundation reinforced composite pile and its construction process to solve the above problems. Summary of the Invention
[0004] In order to overcome the above-mentioned technical problems, the purpose of the present invention is to provide a soft foundation rigid composite pile and its construction process, so as to solve the problem proposed in the above-mentioned background technology that the strength of the cement soil pile body and the degree of pile side friction resistance are greatly affected by factors such as soil quality and groundwater, precast concrete piles are prone to deflection when pressed in, and precast piles are driven into cement soil, and the squeezing effect causes a large excess pore water pressure in the soft clay around the pile.
[0005] To achieve the above-mentioned purpose, the present invention provides the following technical solution: a soft foundation rigid composite pile and its construction process, including a limiting bracket, a steel pipe, a cement-soil mixing pile and a precast concrete pipe pile, wherein a limiting bracket is installed on the top of the cement-soil mixing pile, a steel pipe is installed in the middle of the limiting bracket, and a precast concrete pipe pile is installed in the middle of the steel pipe.
[0006] Preferably, the cement soil mixing pile is a wet cement soil mixing pile, and the pile diameter D of the cement soil mixing pile is 700 mm.
[0007] Preferably, the precast concrete pipe pile is a prestressed concrete pipe pile, and the pile diameter D of the precast concrete pipe pile is 400 mm.
[0008] Preferably, a steel pipe is installed in the middle of the limiting bracket, and the bottom of the steel pipe is fixedly connected to the connecting ring.
[0009] Preferably, a plurality of plastic drainage boards are installed on the outside of the steel pipe.
[0010] Preferably, one end of the plastic drain board is fixedly connected to the connecting ring, and the other end of the plastic drain board is connected to the vacuum tube.
[0011] Preferably, the limiting bracket includes a steel plate, a support column, a limiting plate and steel pins.
[0012] Preferably, the top of the steel plate is fixedly connected to four support columns, the top of the support column is fixedly connected to a limiting plate, and the steel plate and the limiting plate are both slidably connected to the steel pipe.
[0013] Preferably, a plurality of steel bar pins are fixedly connected to the bottom of the steel plate, and the bottoms of the steel bar pins are spherical.
[0014] Preferably, a soft foundation reinforced composite pile and its construction process and construction method include the following steps:
[0015] Step S1: clearing the surface and backfilling, setting out the pile position, inspecting and adjusting the drilling rig in place, drilling to the designed depth according to the preset pile diameter and length using a forward cycle, turning on the high-pressure grouting pump, raising the drill in a reverse cycle, and spraying cement slurry to 0.3 m below the working reference surface, repeatedly stirring and drilling to the designed depth, raising the drill in a reverse cycle, and spraying cement slurry to the surface;
[0016] Step S2: Lay the limit bracket on the top of the cement-soil mixing pile, lift the steel pipe, insert the steel pipe into the middle of the limit bracket, align it with the circular hole between the steel plate and the limit plate, adjust the verticality, start the vibration equipment to press the steel pipe into the designed elevation, and ensure that the upper end of the steel casing is more than 1.0m above the ground;
[0017] Step S3: Lay out vacuum pipes, install vacuum equipment, check sealing performance, and perform vacuuming;
[0018] Step S4: Check the position of the precast concrete pipe pile, put the pile driver in place, statically press the precast concrete pipe pile, and sink the pile to the designed depth;
[0019] Step S5, start the crane and pull out the steel pipe. After the pipe pulling is completed, inject concrete slurry into the gap between the precast concrete pipe pile and the cement soil mixing pile to form an interlocking contact, and wait for the cement soil mixing pile to solidify and take shape, thus completing the construction.
[0020] Compared with the prior art, the present invention has the following beneficial effects:
[0021] 1. A soft foundation reinforced composite pile and its construction process are provided with a limit bracket and a steel pipe. The limit bracket is inserted into the top surface of the cement soil mixing pile. The steel plate can be stably and firmly installed on the top surface of the cement soil mixing pile through the steel pins to prevent it from tilting or shaking. The steel pipe is lifted and adjusted vertically. It is inserted into the circular hole between the steel plate and the limit plate. The steel plate and the limit plate are used to ensure that the steel pipe is located in the center of the cement soil pile and will not deflect when pressed in. The position of the precast concrete pipe pile is checked, the pile driver is in place, and the precast concrete pipe pile is put into place. Concrete pipe piles are inserted into steel pipes, and then statically pressurized precast concrete pipe piles are sunk to the designed depth. Precast concrete pipe piles are driven into cement soil through the steel pipes, which does not require large energy consumption and will not squeeze the cement soil mixing piles outside the steel pipes. This solves the problem of large excess pore water pressure in the soft clay around the piles caused by squeezing. The crane is started and the steel pipe is pulled out. After the pipe is pulled out, concrete slurry is injected into the gap between the precast concrete pipe pile and the cement soil mixing pile to form an interlocking contact, and the cement soil mixing pile is left to solidify and take shape.
[0022] 2. The soft foundation reinforced composite pile and its construction process are provided with a plastic drainage board and a vacuum tube. The vacuum tube is laid and the plastic drainage board is connected in series. The vacuum equipment is installed, the sealing performance is tested, and the vacuum is drawn. The excess moisture in the cement soil mixing pile is absorbed by the plastic drainage board and the vacuum tube, so that it is not affected by the moisture of the soft soil, thereby ensuring the quality of the pile. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Figure 1 It is a front perspective schematic diagram of the present invention;
[0024] Figure 2 This is a schematic diagram of the explosion structure of the present invention;
[0025] Figure 3 This is a schematic diagram of the explosion structure of the limiting bracket of the present invention;
[0026] Figure 4 This is a schematic diagram of the present invention when the limiting bracket is inserted;
[0027] Figure 5 This is a schematic diagram of the present invention when a steel pipe and a plastic drain board are inserted;
[0028] Figure 6 A schematic diagram of the present invention when inserting precast concrete piles;
[0029] Figure 7 This is a schematic diagram of the present invention when the steel pipe and the plastic drain board are removed.
[0030] In the figure: 1. Limit bracket; 11. Steel plate; 12. Support column; 13. Limit plate; 14. Steel bar pin; 2. Steel pipe; 3. Connecting ring; 4. Plastic drainage board; 5. Vacuum tube; 6. Cement-soil mixing pile; 7. Precast concrete pipe pile. DETAILED DESCRIPTION
[0031] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.
[0032] See also Figure 1-7 The present invention provides an embodiment: a soft foundation rigid composite pile and its construction process, including a limiting bracket 1, a steel pipe 2, a cement soil mixing pile 6 and a precast concrete pipe pile 7. The limiting bracket 1 is installed on the top of the cement soil mixing pile 6, the steel pipe 2 is installed in the middle of the limiting bracket 1, and the precast concrete pipe pile 7 is installed in the middle of the steel pipe 2. The precast concrete pipe pile 7 is driven into the cement soil through the steel pipe 2 without consuming a lot of energy and without squeezing the cement soil mixing pile 6 outside the steel pipe 2, thereby solving the problem of large excess pore water pressure in the soft clay around the pile caused by squeezing.
[0033] The cement soil mixing pile 6 is a wet cement soil mixing pile 6 , and the pile diameter D of the cement soil mixing pile 6 is 700 mm.
[0034] The precast concrete pipe pile 7 is a prestressed concrete pipe pile, and the pile diameter D of the precast concrete pipe pile is 400 mm.
[0035] A steel pipe 2 is installed in the middle of the limiting bracket 1, and the bottom of the steel pipe 2 is fixedly connected to the connecting ring 3.
[0036] Several plastic drainage boards 4 are installed on the outside of the steel pipe 2.
[0037] One end of the plastic drain board 4 is fixedly connected to the connecting ring 3, and the other end of the plastic drain board 4 is connected to the vacuum tube 5. The plastic drain board 4 and the vacuum tube 5 absorb excess moisture in the cement-soil mixing pile 6, so that it is not affected by the moisture in the soft soil, thereby ensuring the quality of the pile.
[0038] The limiting bracket 1 includes a steel plate 11 , a support column 12 , a limiting plate 13 and steel bar pins 14 .
[0039] The top of the steel plate 11 is fixedly connected to four support columns 12, and the top of the support column 12 is fixedly connected to the limit plate 13. The steel plate 11 and the limit plate 13 are both slidably connected to the steel pipe 2. The steel plate 11 and the limit plate 13 ensure that the steel pipe 2 is located in the center of the cement soil pile and will not deflect when pressed in.
[0040] The bottom of the steel plate 11 is fixedly connected to a number of steel pins 14, the bottom of the steel pins 14 is spherical, and the steel pins 14 enable the steel plate 11 to be stably and firmly installed on the top surface of the cement soil mixing pile to prevent it from tilting or shaking.
[0041] A soft foundation reinforced composite pile and its construction process and method, comprising the following steps:
[0042] Step S1: clearing the surface and backfilling, setting out the pile position, inspecting and adjusting the drilling rig in place, drilling to the designed depth according to the preset pile diameter and length using a forward cycle, turning on the high-pressure grouting pump, raising the drill in a reverse cycle, and spraying cement slurry to 0.3 m below the working reference surface, repeatedly stirring and drilling to the designed depth, raising the drill in a reverse cycle, and spraying cement slurry to the surface;
[0043] Step S2: The limiting bracket 1 is laid on the top of the cement-soil mixing pile 6, the steel pipe 2 is lifted, and the steel pipe 2 is inserted into the middle of the limiting bracket, aligned with the circular hole between the steel plate 11 and the limiting plate 13, and the verticality is adjusted. The vibration equipment is started to press the steel pipe 2 to the designed elevation, and the upper end of the steel casing is ensured to be more than 1.0m above the ground.
[0044] Step S3, laying the vacuum pipe 5, installing the vacuum equipment, checking the sealing performance, and vacuuming;
[0045] Step S4, checking the position of the precast concrete pipe pile 7, putting the pile driver in place, statically pressing the precast concrete pipe pile 7, and sinking the pile to the designed depth;
[0046] Step S5, start the crane and pull out the steel pipe 2. After the pipe pulling is completed, inject concrete slurry into the gap between the precast concrete pipe pile 7 and the cement soil mixing pile 6 to form an interlocking contact, and wait for the cement soil mixing pile 6 to solidify and form, and the construction is completed.
[0047] Working principle:
[0048] When in use, cement is used as a curing agent, and a special mixing machine is used to force the soft soil and the curing agent to be mixed deep in the foundation. A series of physical and chemical reactions between the curing agent and the soft soil are used to harden the soft soil into a high-quality foundation with integrity, water stability and a certain strength. The cement slurry pressed into the soft soil is forced to mix with the surrounding soft soil with the rotating mixing blades to form a mud reinforcement body. The limit bracket 1 is inserted into the top surface of the cement soil mixing pile 6, and the steel plate 11 can be stably and firmly installed on the top surface of the cement soil mixing pile 6 through the steel pins 14 to prevent it from tilting or shaking. The steel pipe 2 is lifted and adjusted. The steel pipe 2 is inserted vertically into the circular hole between the steel plate 11 and the limiting plate 13. The steel plate 11 and the limiting plate 13 ensure that the steel pipe 2 is located at the center of the cement soil pile and does not deflect when pressed in. The vacuum pipe 5 is laid and connected in series with the plastic drain plate 4. The vacuum equipment is installed, the sealing performance is tested, and the vacuum is applied. The plastic drain plate 4 and the vacuum pipe 5 absorb the excess water in the cement soil mixing pile 6, so that it is not affected by the moisture in the soft soil, thus ensuring the quality of the pile. Prestressed concrete pipe piles are a kind of tubular slender member driven into the soil with a cross-sectional dimension much smaller than its length. The upper part of the pipe pile is connected to the pedestal (beam) to form the pile foundation. Its foundation structure is a prestressed concrete structure, which can be divided into post-tensioned prestressed pipe piles and pre-tensioned prestressed pipe piles. The upper load is transferred to the soil layer through the pile foundation. It is a common form of deep foundation and can well adapt to various soft geological conditions and load conditions. It has the characteristics of large bearing capacity, good stability, small settlement value, etc. It can also be mechanized for construction, greatly improving the construction progress. For itself, prestressed concrete pipe piles greatly reduce their own weight, thereby saving materials and enhancing their tensile properties. In general, factory prefabrication should be adopted to ensure the quality of the finished piles and at the same time have the characteristics of flexible construction. The position of the precast concrete pipe pile 7 is checked, the pile driver is in place, the precast concrete pipe pile 7 is inserted into the steel pipe 2, and then the precast concrete pipe pile 7 is statically pressed and sunk to the designed depth. The precast concrete pipe pile 7 is driven into the cement soil through the steel pipe 2, which does not require large energy consumption and will not squeeze the cement soil mixing pile 6 outside the steel pipe 2, solving the problem of large excess pore water pressure in the soft clay around the pile caused by squeezing. The crane is started and the steel pipe 2 is pulled out. After the pipe pulling is completed, concrete slurry is injected into the gap between the precast concrete pipe pile 7 and the cement soil mixing pile 6 to form a bite contact, and the cement soil mixing pile 6 is waited for to solidify and take shape.
[0049] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims, not the foregoing description, and all variations within the meaning and range of equivalents of the claims are intended to be included therein. Any reference sign in a claim should not be construed as limiting the claim to which it relates.
Claims
1. A soft foundation reinforced composite pile and its construction process, comprising a limit bracket (1), a steel pipe (2), a cement soil mixing pile (6) and a precast concrete pipe pile (7), characterized in that: A limit bracket (1) is installed on the top of the cement-soil mixing pile (6), a steel pipe (2) is installed in the middle of the limit bracket (1), and a precast concrete pipe pile (7) is installed in the middle of the steel pipe (2).
2. A soft foundation reinforced composite pile and its construction process according to claim 1, characterized in that: The cement soil mixing pile (6) is a wet cement soil mixing pile (6), and the pile diameter D of the cement soil mixing pile (6) is 700 mm.
3. The soft foundation reinforced composite pile and its construction process according to claim 1, characterized in that: The prefabricated concrete pipe pile (7) is a prestressed concrete pipe pile, and the pile diameter D of the prefabricated pipe pile is 400 mm.
4. The soft foundation reinforced composite pile and its construction process according to claim 1, characterized in that: A steel pipe (2) is installed in the middle of the limiting bracket (1), and the bottom of the steel pipe (2) is fixedly connected to a connecting ring (3).
5. The soft foundation reinforced composite pile and its construction process according to claim 4, characterized in that: A plurality of plastic drainage boards (4) are installed on the outside of the steel pipe (2).
6. The soft foundation reinforced composite pile and its construction process according to claim 5, characterized in that: One end of the plastic drain plate (4) is fixedly connected to the connecting ring (3), and the other end of the plastic drain plate (4) is connected to the vacuum tube (5).
7. The soft foundation reinforced composite pile and its construction process according to claim 1, characterized in that: The position-limiting bracket (1) comprises a steel plate (11), a support column (12), a position-limiting plate (13) and steel bar pins (14).
8. The soft foundation reinforced composite pile and its construction process according to claim 7, characterized in that: The top of the steel plate (11) is fixedly connected to four support columns (12), the top of the support column (12) is fixedly connected to a limit plate (13), and both the steel plate (11) and the limit plate (13) are slidably connected to the steel pipe (2).
9. The soft foundation reinforced composite pile and its construction process according to claim 8, characterized in that: The bottom of the steel plate (11) is fixedly connected to a plurality of steel bar pins (14), and the bottom of the steel bar pins (14) is spherical.
10. A construction method for a soft foundation reinforced composite pile and its construction process as claimed in any one of claims 1 to 9, comprising the following steps: Step S1: clearing the surface and backfilling, setting out the pile position, inspecting and adjusting the drilling rig in place, drilling to the designed depth according to the preset pile diameter and length using a forward cycle, turning on the high-pressure grouting pump, raising the drill in a reverse cycle, and spraying cement slurry to 0.3 m below the working reference surface, repeatedly stirring and drilling to the designed depth, raising the drill in a reverse cycle, and spraying cement slurry to the surface; Step S2, the limiting bracket (1) is laid on the top of the cement-soil mixing pile (6), the steel pipe (2) is lifted, the steel pipe (2) is inserted into the middle of the limiting bracket, the circular hole between the steel plate (11) and the limiting plate (13) is aligned, and the verticality is adjusted. The vibration equipment is started to press the steel pipe (2) to the designed elevation, and the upper end of the steel casing is ensured to be more than 1.0 m above the ground; Step S3, laying the vacuum pipe (5), installing the vacuum equipment, checking the sealing performance, and vacuuming; Step S4, checking the position of the precast concrete pipe pile (7), putting the pile driver in place, statically pressing the precast concrete pipe pile (7), and sinking the pile to the designed depth; Step S5, start the crane and pull out the steel pipe (2). After the pipe pulling is completed, inject concrete slurry into the gap between the precast concrete pipe pile (7) and the cement soil mixing pile (6) to form an interlocking contact, wait for the cement soil mixing pile (6) to solidify and form, and then complete the construction.