Prestressed pipe pile reinforcing process

Abstract

The invention relates to a prestressed pipe pile reinforcing process in the technical field of building reinforcement. The prestressed pipe pile reinforcing process comprises the following steps of S1, site investigation, S2, material preparation, S3, preparation before construction, S4, piling construction, S5, pipe pile reinforcement, S6, secondary piling reinforcement, S7, grouting construction and S8, quality detection. The mode that the through holes are formed in the surface of the pipe pile is adopted, the longitudinal strength and the transverse strength of the pile body are improved by inserting the reinforcing rods, the pipe pile can bear larger loads, and the lateral stability is improved; new prestressed pipe piles are driven into original pipe piles to form a dual-supporting structure, the overall bearing capacity of the pipe piles is greatly improved, the new and old pipe piles bear loads together, load distribution is more uniform, stress of a single pipe pile is reduced, the overall rigidity of a pile body is enhanced through combination of the new and old pipe piles, and the service life of the pile body is prolonged. The possibility of bending deformation is reduced; and the lateral stability is improved.

Description

Technical Field

[0001] The invention relates to the technical field of building reinforcement, in particular to a prestressed pipe pile reinforcement process. Background Art

[0002] Prestressed pipe piles are high-strength concrete pipe piles that have been processed through a special manufacturing process and are widely used in building foundation projects. They enhance their bending and tensile properties by applying prestress during the production process, thereby improving the stability and bearing capacity of the overall structure. Prestressed pipe pile reinforcement is an effective foundation treatment method that is widely used to improve the bearing capacity, stability and durability of the foundation of existing buildings or infrastructure. By adding prestressed pipe piles to the original foundation, the overall performance of the structure can be significantly improved to adapt to different geological conditions and construction requirements.

[0003] Most of the existing prestressed pipe pile reinforcements use concrete to pour the interior of the pipe pile to form a whole, but the exterior is still a smooth surface, which does not have the effect of forming a grip. When the soil layer seeps water and becomes soft, since the smooth surface does not have the function of forming a grip, it may tilt and cause collapse. On the other hand, since the smooth surface does not have the function of forming a grip, it is unable to grip the surrounding soil layer. When tilting occurs, landslides may occur. Therefore, it is necessary to further process and improve its structure, which increases the process and reduces work efficiency. For this reason, the inventors propose a prestressed pipe pile reinforcement process to solve the above-mentioned technical problems. Summary of the invention

[0004] In order to overcome the above-mentioned shortcomings, the invention aims to provide a technical solution that can solve the above-mentioned problems.

[0005] A prestressed pipe pile reinforcement process, the method comprising the following steps:

[0006] S1: Site survey: Conduct a detailed geological survey of the construction site to understand the nature of the foundation soil, groundwater level, and the structural conditions of existing buildings. Based on the site survey results, design the layout of prestressed pipe piles, including the number, location, length, and diameter of the pipe piles;

[0007] S2: Material preparation: prepare the required prestressed pipe piles, concrete, steel bars, grouting materials, pile drivers, drilling equipment, and grouting equipment;

[0008] S3: Preparation before construction: clean up the construction site, ensure that there are no obstacles in the construction area, measure and lay out the lines on site according to the design drawings, determine the location of each pile, and set up fences and safety signs;

[0009] S4: Pile construction: Use drilling equipment to drill holes at the predetermined location, with the hole diameter larger than the diameter of the prestressed pipe pile, hoist the prestressed pipe pile into the drilled hole, ensure that the pile body is vertical, and drive the prestressed pipe pile into the soil layer by using a pile driver until it reaches the designed depth, check and correct the position and verticality of the pile to ensure that it meets the design requirements;

[0010] S5: Pipe pile reinforcement: a through hole is opened on the surface of the pipe pile so that the through hole penetrates the surface of the pipe pile, and then a reinforcing rod is placed inside the through hole, one end of the reinforcing rod is extended to the hollow part inside the pipe pile, and after the pipe pile is fixed, a plug is pressed into the inside of the pipe pile by a packing method. After the plug is pressed in, the pressure generated by the plug pushes the reinforcing rod out of the through hole and into the soil layer, thereby obtaining a reinforced pipe pile;

[0011] The insertion of the reinforcement rod increases the longitudinal and transverse strength of the pile body, allowing the pipe pile to withstand greater loads and improve lateral stability. After the reinforcement rod is inserted into the soil layer, the friction between the pipe pile and the surrounding soil is enhanced, the lateral stability and bending resistance are improved, the bending deformation of the pipe pile when subjected to force is reduced, the rigidity of the overall structure is improved, and the external force can be better dispersed to avoid local stress concentration, reducing the risk of damage caused by stress concentration. In addition, after the reinforcement rod is inserted into the soil layer, it is equivalent to providing an additional anchor point for the pipe pile, which significantly improves the pull-out resistance. In the case of a high groundwater level or buoyancy, the reinforcement rod can effectively prevent the pipe pile from floating, ensure its stability, and play a role in reinforcing the stability of the pipe pile installation;

[0012] S6: Secondary piling reinforcement: hoist another prestressed pipe pile with a diameter smaller than the middle hole of the reinforced pipe pile into the hole of the reinforced pipe pile, ensure that the pile body is vertical, and drive the prestressed pipe pile into the interior of the reinforced pipe pile by using a pile driver until it reaches the designed depth, check and correct the position and verticality of the pile to ensure that it meets the design requirements, and obtain a secondary reinforced pipe pile;

[0013] By driving new prestressed pipe piles into the original pipe piles, a double support structure is formed, which greatly improves the overall bearing capacity of the pipe piles. The new and old pipe piles bear the load together, making the load distribution more uniform and reducing the force on a single pipe pile. The combination of the new and old pipe piles enhances the overall rigidity of the pile body, reduces the possibility of bending deformation, and improves lateral stability. The nested structure of the inner and outer layers of pipe piles increases lateral stability, and the effect is more obvious in soft soil foundations.

[0014] In addition, the newly driven prestressed pipe piles can penetrate deeper into the ground, providing additional anchor points and significantly improving the pull-out resistance. When the groundwater level is high or there is buoyancy, the inner pipe piles can effectively prevent the outer pipe piles from floating up, ensuring their stability. In addition, due to the close combination of the inner and outer pipe piles, the need for later maintenance is reduced, reducing maintenance costs.

[0015] S7: Grouting construction: remove the debris and mud in the hole to ensure that the hole is clean, insert the grouting pipe into the reserved hole inside or outside the prestressed pipe pile, and inject cement mortar or chemical grouting material into the hole through the grouting pipe to fill the pores and increase the friction between the pile and the soil layer. After the grouting is completed, let it stand to ensure that the grouting material is fully hardened;

[0016] Grouting materials are used to fill the pores inside the pile body and the surrounding soil layer to form a dense whole, which increases the contact area between the pile and the soil layer. After the grouting materials are solidified, they can significantly increase the friction between the pile and the soil layer, and improve the lateral friction resistance and end bearing capacity of the pile. After filling the voids inside the pile body, the bending deformation of the pile body when subjected to force is reduced, and the rigidity of the overall structure is improved. On the other hand, the grouting materials enable the external force to be more evenly distributed on the pile body, avoiding local stress concentration and reducing the risk of damage caused by stress concentration.

[0017] S8: Quality inspection: After reinforcement, the secondary reinforcement piles are regularly monitored to observe whether there is new settlement or tilt. According to the monitoring results, maintenance and upkeep are carried out to ensure the safety and stability of the building;

[0018] Settlement monitoring includes leveling, using a level to regularly measure the height changes at different locations of the building, recording the settlement amount, installing settlement plates at designated locations, and monitoring the settlement by regularly measuring their height changes;

[0019] Tilt monitoring uses electronic inclinometers or mechanical inclinometers to monitor the tilt angle of the building in real time. Laser rangefinders can also be used to measure the relative displacement between different parts of the building to determine whether there is a tilt phenomenon.

[0020] Maintenance work includes crack monitoring and stress monitoring. Crack monitoring monitors the development of cracks on the surface and inside of the building by installing crack meters, or by conducting regular visual inspections to record the location, length and width changes of cracks. Stress monitoring monitors the stress changes in reinforced concrete structures by installing strain gauges at designated locations. Pressure sensors can also be installed inside the pipe piles to monitor the changes in pressure of the soil on the pipe piles.

[0021] Furthermore, in S1, the properties of the foundation soil layer are soft soil layer, medium hardness soil layer and hard soil layer:

[0022] Soft soil layers include silt and muddy soil. Such soil layers usually have low bearing capacity, high compressibility, and are prone to settlement. Prestressed pipe piles can penetrate these soft soil layers to achieve a more stable bearing layer.

[0023] Soft soil layers include silt and silty clay. This type of soil layer is more stable than silt and has a certain degree of compressibility. It is suitable for the installation of prestressed pipe piles. Prestressed pipe piles can provide additional support and improve the bearing capacity of the foundation.

[0024] Medium hardness soil layers include sand and silt. Sand and silt layers have good permeability and low compressibility. Prestressed pipe piles can obtain good friction in this type of soil layer to improve the stability of the foundation.

[0025] The medium-hard soil layer includes the clay layer, which has high plasticity and cohesion. The prestressed pipe piles can improve the bearing capacity of the foundation through the combined effect of friction and end bearing force.

[0026] Hard soil layers include dense sand and gravel, which have high bearing capacity and low compressibility. Prestressed pipe piles can use the high strength of these soil layers to provide support through end bearing.

[0027] Furthermore, in S1, the influence of the groundwater level is that the groundwater level should be lower than the pile bottom elevation by ≥1 meter to ensure the dryness of the pile hole and the safety of construction; when the groundwater level is higher than 1 meter, well point dewatering or drainage measures can be adopted to lower the groundwater level, reduce the water content of the soil layer, and improve the shear strength of the soil, or the casing method can be used to prevent groundwater from entering the pile hole.

[0028] Further, in said S5, the angle between the through hole and the pipe pile is 45°, the plug is 1 / 20 of the total length of the pipe pile, the plug is trapezoidal, and the smaller end of the plug enters the interior of the pipe pile first;

[0029] The 45° bevel design between the through hole and the pipe pile can optimize the stress transfer path. This angle makes the stress more evenly distributed between the pipe pile and the reinforcement rod, reducing local stress concentration, thereby improving the stability of the overall structure. The bevel design can also reduce the bending deformation of the pipe pile when subjected to force and enhance the bending resistance. The smaller end of the plug is inserted into the pipe pile first, which makes it easier for the plug to pass through the through hole into the predetermined position, reducing the difficulty of construction and making it easier for the plug to push the reinforcement rod, so that the reinforcement rod is embedded in the soil layer.

[0030] Furthermore, in S6, another prestressed pipe pile smaller than the diameter of the middle hole of the reinforced pipe pile is hoisted into the hole of the reinforced pipe pile, wherein the outer diameter of the prestressed pipe pile is consistent with the diameter of the middle hole of the reinforced pipe pile, and the outer side surface of the prestressed pipe pile is in contact with the inner wall of the reinforced pipe pile; the inner and outer layers of the pipe piles form a double support structure, which significantly improves the overall bearing capacity, and the inner and outer pipe piles jointly bear the load, making the load distribution more uniform, reducing the force on a single pipe pile, and playing a reinforcement role.

[0031] Furthermore, in S7, the standing time is 24h-72h, and the curing time is 7-14 days; during the standing period, the influence of external loads or disturbances on the materials can be avoided, and the risk of damage caused by early stress can be reduced. Through sufficient standing and curing, the possibility of rework due to incomplete hardening of materials can be reduced, thereby improving construction efficiency. In addition, fully hardened materials enhance the stability and safety of the overall structure, avoid safety hazards caused by incomplete hardening of materials, and at the same time show better stability and impact resistance under extreme conditions such as earthquakes.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] 1. A through hole is opened on the surface of the pipe pile so that the through hole penetrates the surface of the pipe pile, and then a reinforcing rod is placed inside the through hole. The plug is pressed into the inside of the pipe pile by means of packing. After the plug is pressed in, the pressure generated by the plug pushes the reinforcing rod out of the through hole and into the soil layer. The insertion of the reinforcing rod increases the longitudinal and transverse strength of the pile body, so that the pipe pile can withstand a larger load and improve the lateral stability;

[0034] 2. After the reinforcement rod is inserted into the soil layer, the friction between the pipe pile and the surrounding soil is enhanced, the lateral stability and bending resistance are improved, the bending deformation of the pipe pile when subjected to force is reduced, the rigidity of the overall structure is improved, and the external force can be better dispersed to avoid local stress concentration, reducing the risk of damage caused by stress concentration. In addition, after the reinforcement rod is inserted into the soil layer, it is equivalent to providing an additional anchor point for the pipe pile, which significantly improves the pull-out resistance. In the case of a high groundwater level or buoyancy, the reinforcement rod can effectively prevent the pipe pile from floating, ensure its stability, and play a role in reinforcing the stability of the pipe pile installation;

[0035] 3. By driving new prestressed pipe piles into the original pipe piles, a double support structure is formed, which greatly improves the overall bearing capacity of the pipe piles. The new and old pipe piles bear the load together, making the load distribution more uniform and reducing the force on a single pipe pile. The combination of the new and old pipe piles enhances the overall rigidity of the pile body, reduces the possibility of bending deformation, and improves lateral stability. The nested structure of the inner and outer layers of pipe piles increases lateral stability, and the effect is more obvious in soft soil foundations.

[0036] 4. The newly driven prestressed pipe piles can penetrate deeper into the ground, providing additional anchoring points and significantly improving the pull-out resistance. When the groundwater level is high or there is buoyancy, the inner pipe piles can effectively prevent the outer pipe piles from floating up, ensuring their stability. In addition, due to the close combination of the inner and outer pipe piles, the need for later maintenance is reduced, reducing maintenance costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1It is a process flow chart of prestressed pipe pile reinforcement technology. DETAILED DESCRIPTION

[0038] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0039] For this example, please refer to Figure 1 , a prestressed pipe pile reinforcement process is specifically implemented, and the method comprises the following steps:

[0040] S1: Site survey: Conduct a detailed geological survey of the construction site to understand the nature of the foundation soil, groundwater level, and the structural conditions of existing buildings. Based on the site survey results, design the layout of prestressed pipe piles, including the number, location, length, and diameter of the pipe piles;

[0041] S2: Material preparation: prepare the required prestressed pipe piles, concrete, steel bars, grouting materials, pile drivers, drilling equipment, and grouting equipment;

[0042] S3: Preparation before construction: clean up the construction site, ensure that there are no obstacles in the construction area, measure and lay out the lines on site according to the design drawings, determine the location of each pile, and set up fences and safety signs;

[0043] S4: Pile construction: Use drilling equipment to drill holes at the predetermined location, with the hole diameter larger than the diameter of the prestressed pipe pile, hoist the prestressed pipe pile into the drilled hole, ensure that the pile body is vertical, and drive the prestressed pipe pile into the soil layer by using a pile driver until it reaches the designed depth, check and correct the position and verticality of the pile to ensure that it meets the design requirements;

[0044] S5: Pipe pile reinforcement: a through hole is opened on the surface of the pipe pile so that the through hole penetrates the surface of the pipe pile, and then a reinforcing rod is placed inside the through hole, one end of the reinforcing rod is extended to the hollow part inside the pipe pile, and after the pipe pile is fixed, a plug is pressed into the inside of the pipe pile by a packing method. After the plug is pressed in, the pressure generated by the plug pushes the reinforcing rod out of the through hole and into the soil layer, thereby obtaining a reinforced pipe pile;

[0045] The insertion of the reinforcement rod increases the longitudinal and transverse strength of the pile body, allowing the pipe pile to withstand greater loads and improve lateral stability. After the reinforcement rod is inserted into the soil layer, the friction between the pipe pile and the surrounding soil is enhanced, the lateral stability and bending resistance are improved, the bending deformation of the pipe pile when subjected to force is reduced, the rigidity of the overall structure is improved, and the external force can be better dispersed to avoid local stress concentration, reducing the risk of damage caused by stress concentration. In addition, after the reinforcement rod is inserted into the soil layer, it is equivalent to providing an additional anchor point for the pipe pile, which significantly improves the pull-out resistance. In the case of a high groundwater level or buoyancy, the reinforcement rod can effectively prevent the pipe pile from floating, ensure its stability, and play a role in reinforcing the stability of the pipe pile installation;

[0046] S6: Secondary piling reinforcement: hoist another prestressed pipe pile with a diameter smaller than the middle hole of the reinforced pipe pile into the hole of the reinforced pipe pile, ensure that the pile body is vertical, and drive the prestressed pipe pile into the interior of the reinforced pipe pile by using a pile driver until it reaches the designed depth, check and correct the position and verticality of the pile to ensure that it meets the design requirements, and obtain a secondary reinforced pipe pile;

[0047] By driving new prestressed pipe piles into the original pipe piles, a double support structure is formed, which greatly improves the overall bearing capacity of the pipe piles. The new and old pipe piles bear the load together, making the load distribution more uniform and reducing the force on a single pipe pile. The combination of the new and old pipe piles enhances the overall rigidity of the pile body, reduces the possibility of bending deformation, and improves lateral stability. The nested structure of the inner and outer layers of pipe piles increases lateral stability, and the effect is more obvious in soft soil foundations.

[0048] In addition, the newly driven prestressed pipe piles can penetrate deeper into the ground, providing additional anchor points and significantly improving the pull-out resistance. When the groundwater level is high or there is buoyancy, the inner pipe piles can effectively prevent the outer pipe piles from floating up, ensuring their stability. In addition, due to the close combination of the inner and outer pipe piles, the need for later maintenance is reduced, reducing maintenance costs.

[0049] S7: Grouting construction: remove the debris and mud in the hole to ensure that the hole is clean, insert the grouting pipe into the reserved hole inside or outside the prestressed pipe pile, and inject cement mortar or chemical grouting material into the hole through the grouting pipe to fill the pores and increase the friction between the pile and the soil layer. After the grouting is completed, let it stand to ensure that the grouting material is fully hardened;

[0050] Grouting materials are used to fill the pores inside the pile body and the surrounding soil layer to form a dense whole, which increases the contact area between the pile and the soil layer. After the grouting materials are solidified, they can significantly increase the friction between the pile and the soil layer, and improve the lateral friction resistance and end bearing capacity of the pile. After filling the voids inside the pile body, the bending deformation of the pile body when subjected to force is reduced, and the rigidity of the overall structure is improved. On the other hand, the grouting materials enable the external force to be more evenly distributed on the pile body, avoiding local stress concentration and reducing the risk of damage caused by stress concentration.

[0051] S8: Quality inspection: After reinforcement, the secondary reinforcement piles are regularly monitored to observe whether there is new settlement or tilt. According to the monitoring results, maintenance and upkeep are carried out to ensure the safety and stability of the building;

[0052] Settlement monitoring includes leveling, using a level to regularly measure the height changes at different locations of the building, recording the settlement amount, installing settlement plates at designated locations, and monitoring the settlement by regularly measuring their height changes;

[0053] Tilt monitoring uses electronic inclinometers or mechanical inclinometers to monitor the tilt angle of the building in real time. Laser rangefinders can also be used to measure the relative displacement between different parts of the building to determine whether there is a tilt phenomenon.

[0054] Maintenance work includes crack monitoring and stress monitoring. Crack monitoring monitors the development of cracks on the surface and inside of the building by installing crack meters, or by conducting regular visual inspections to record the location, length and width changes of cracks. Stress monitoring monitors the stress changes in reinforced concrete structures by installing strain gauges at designated locations. Pressure sensors can also be installed inside the pipe piles to monitor the changes in pressure of the soil on the pipe piles.

[0055] In S1, the properties of the foundation soil layer are soft soil layer, medium hardness soil layer and hard soil layer:

[0056] Soft soil layers include silt and muddy soil. Such soil layers usually have low bearing capacity, high compressibility, and are prone to settlement. Prestressed pipe piles can penetrate these soft soil layers to achieve a more stable bearing layer.

[0057] Soft soil layers include silt and silty clay. This type of soil layer is more stable than silt and has a certain degree of compressibility. It is suitable for the installation of prestressed pipe piles. Prestressed pipe piles can provide additional support and improve the bearing capacity of the foundation.

[0058] Medium hardness soil layers include sand and silt. Sand and silt layers have good permeability and low compressibility. Prestressed pipe piles can obtain good friction in this type of soil layer to improve the stability of the foundation.

[0059] The medium-hard soil layer includes the clay layer, which has high plasticity and cohesion. The prestressed pipe piles can improve the bearing capacity of the foundation through the combined effect of friction and end bearing force.

[0060] Hard soil layers include dense sand and gravel, which have high bearing capacity and low compressibility. Prestressed pipe piles can use the high strength of these soil layers to provide support through end bearing.

[0061] In S1, the influence of the groundwater level is that the groundwater level should be lower than the pile bottom elevation by ≥1 meter to ensure the dryness of the pile hole and the safety of construction; when the groundwater level is higher than 1 meter, well point dewatering or drainage measures can be adopted to lower the groundwater level, reduce the water content of the soil layer, and improve the shear strength of the soil, or the casing method can be used to prevent groundwater from entering the pile hole.

[0062] In S5, the angle between the through hole and the pipe pile is 45°, the plug is 1 / 20 of the total length of the pipe pile, the plug is trapezoidal, and the smaller end of the plug enters the interior of the pipe pile first;

[0063] The 45° bevel design between the through hole and the pipe pile can optimize the stress transfer path. This angle makes the stress more evenly distributed between the pipe pile and the reinforcement rod, reducing local stress concentration, thereby improving the stability of the overall structure. The bevel design can also reduce the bending deformation of the pipe pile when subjected to force and enhance the bending resistance. The smaller end of the plug is inserted into the pipe pile first, which makes it easier for the plug to pass through the through hole into the predetermined position, reducing the difficulty of construction and making it easier for the plug to push the reinforcement rod, so that the reinforcement rod is embedded in the soil layer.

[0064] In S6, another prestressed pipe pile smaller than the diameter of the middle hole of the reinforced pipe pile is hoisted into the hole of the reinforced pipe pile, wherein the outer diameter of the prestressed pipe pile is consistent with the diameter of the middle hole of the reinforced pipe pile, and the outer side surface of the prestressed pipe pile is in contact with the inner wall of the reinforced pipe pile; the inner and outer layers of the pipe piles form a double support structure, which significantly improves the overall bearing capacity, and the inner and outer pipe piles jointly bear the load, making the load distribution more uniform, reducing the force on a single pipe pile, and playing a reinforcement role.

[0065] In S7, the standing time is 24h-72h, and the curing time is 7-14 days; during the standing period, the influence of external loads or disturbances on the materials can be avoided, and the risk of damage caused by early stress can be reduced. Through sufficient standing and curing, the possibility of rework due to incomplete hardening of materials can be reduced, thereby improving construction efficiency. In addition, fully hardened materials enhance the stability and safety of the overall structure, avoid safety hazards caused by incomplete hardening of materials, and at the same time show better stability and impact resistance under extreme conditions such as earthquakes.

[0066] The design key points of the present invention are:

[0067] 1. A through hole is opened on the surface of the pipe pile so that the through hole penetrates the surface of the pipe pile, and then a reinforcing rod is placed inside the through hole. The plug is pressed into the inside of the pipe pile by means of packing. After the plug is pressed in, the pressure generated by the plug pushes the reinforcing rod out of the through hole and into the soil layer. The insertion of the reinforcing rod increases the longitudinal and transverse strength of the pile body, so that the pipe pile can withstand a larger load and improve the lateral stability;

[0068] 2. After the reinforcement rod is inserted into the soil layer, the friction between the pipe pile and the surrounding soil is enhanced, the lateral stability and bending resistance are improved, the bending deformation of the pipe pile when subjected to force is reduced, the rigidity of the overall structure is improved, and the external force can be better dispersed to avoid local stress concentration, reducing the risk of damage caused by stress concentration. In addition, after the reinforcement rod is inserted into the soil layer, it is equivalent to providing an additional anchor point for the pipe pile, which significantly improves the pull-out resistance. In the case of a high groundwater level or buoyancy, the reinforcement rod can effectively prevent the pipe pile from floating, ensure its stability, and play a role in reinforcing the stability of the pipe pile installation;

[0069] 3. By driving new prestressed pipe piles into the original pipe piles, a double support structure is formed, which greatly improves the overall bearing capacity of the pipe piles. The new and old pipe piles bear the load together, making the load distribution more uniform and reducing the force on a single pipe pile. The combination of the new and old pipe piles enhances the overall rigidity of the pile body, reduces the possibility of bending deformation, and improves lateral stability. The nested structure of the inner and outer layers of pipe piles increases lateral stability, and the effect is more obvious in soft soil foundations.

[0070] 4. The newly driven prestressed pipe piles can penetrate deeper into the ground, providing additional anchoring points and significantly improving the pull-out resistance. When the groundwater level is high or there is buoyancy, the inner pipe piles can effectively prevent the outer pipe piles from floating up, ensuring their stability. In addition, due to the close combination of the inner and outer pipe piles, the need for later maintenance is reduced, reducing maintenance costs.

[0071] The above contents are further detailed descriptions of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as the protection scope of the present invention.

Claims

1. A prestressed pipe pile reinforcement process, characterized in that: The method comprises the following steps: S1: Site survey: Conduct a detailed geological survey of the construction site to understand the nature of the foundation soil, groundwater level, and the structural conditions of existing buildings. Based on the site survey results, design the layout of prestressed pipe piles, including the number, location, length, and diameter of the pipe piles; S2: Material preparation: prepare the required prestressed pipe piles, concrete, steel bars, grouting materials, pile drivers, drilling equipment, and grouting equipment; S3: Preparation before construction: clean up the construction site, ensure that there are no obstacles in the construction area, measure and lay out the lines on site according to the design drawings, determine the location of each pile, and set up fences and safety signs; S4: Pile construction: Use drilling equipment to drill holes at the predetermined location, with the hole diameter larger than the diameter of the prestressed pipe pile, hoist the prestressed pipe pile into the drilled hole, ensure that the pile body is vertical, and drive the prestressed pipe pile into the soil layer by using a pile driver until it reaches the designed depth, check and correct the position and verticality of the pile to ensure that it meets the design requirements; S5: Pipe pile reinforcement: a through hole is opened on the surface of the pipe pile so that the through hole penetrates the surface of the pipe pile, and then a reinforcing rod is placed inside the through hole, one end of the reinforcing rod is extended to the hollow part inside the pipe pile, and after the pipe pile is fixed, a plug is pressed into the inside of the pipe pile by a packing method. After the plug is pressed in, the pressure generated by the plug pushes the reinforcing rod out of the through hole and into the soil layer, thereby obtaining a reinforced pipe pile; S6: Secondary piling reinforcement: hoist another prestressed pipe pile with a diameter smaller than the middle hole of the reinforced pipe pile into the hole of the reinforced pipe pile, ensure that the pile body is vertical, and drive the prestressed pipe pile into the interior of the reinforced pipe pile by using a pile driver until it reaches the designed depth, check and correct the position and verticality of the pile to ensure that it meets the design requirements, and obtain a secondary reinforced pipe pile; S7: Grouting construction: remove the debris and mud in the hole to ensure that the hole is clean, insert the grouting pipe into the reserved hole inside or outside the prestressed pipe pile, and inject cement mortar or chemical grouting material into the hole through the grouting pipe to fill the pores and increase the friction between the pile and the soil layer. After the grouting is completed, let it stand to ensure that the grouting material is fully hardened; S8: Quality inspection: After reinforcement, the secondary reinforcement piles are regularly monitored to observe whether there is new settlement or tilt. Based on the monitoring results, maintenance work is carried out to ensure the safety and stability of the building.

2. A prestressed pipe pile reinforcement process according to claim 1, characterized in that: In S1, the properties of the foundation soil layer are soft soil layer, medium hardness soil layer and hard soil layer: Soft soil layers include silt and muddy soil. Such soil layers usually have low bearing capacity, high compressibility, and are prone to settlement. Prestressed pipe piles can penetrate these soft soil layers to achieve a more stable bearing layer. Soft soil layers include silt and silty clay. This type of soil layer is more stable than silt and has a certain degree of compressibility. It is suitable for the installation of prestressed pipe piles. Prestressed pipe piles can provide additional support and improve the bearing capacity of the foundation. Medium hardness soil layers include sand and silt. Sand and silt layers have good permeability and low compressibility. Prestressed pipe piles can obtain good friction in this type of soil layer to improve the stability of the foundation. The medium-hard soil layer includes the clay layer, which has high plasticity and cohesion. The prestressed pipe piles can improve the bearing capacity of the foundation through the combined effect of friction and end bearing force. Hard soil layers include dense sand and gravel, which have high bearing capacity and low compressibility. Prestressed pipe piles can use the high strength of these soil layers to provide support through end bearing.

3. The prestressed pipe pile reinforcement process according to claim 1, characterized in that: In S1, the influence of the groundwater level is that the groundwater level should be lower than the pile bottom elevation by ≥1 meter to ensure the dryness in the pile hole and the safety of construction.

4. A prestressed pipe pile reinforcement process according to any one of claims 1 to 3, characterized in that: In S5, the angle between the through hole and the pipe pile is 45°, the plug is 1 / 20 of the total length of the pipe pile, the plug is trapezoidal, and the smaller end of the plug enters the interior of the pipe pile first.

5. A prestressed pipe pile reinforcement process according to any one of claims 1 to 3, characterized in that: In S6, another prestressed pipe pile with a smaller diameter than the middle hole of the reinforced pipe pile is hoisted into the hole of the reinforced pipe pile, wherein the outer diameter of the prestressed pipe pile is consistent with the diameter of the middle hole of the reinforced pipe pile, and the outer side surface of the prestressed pipe pile is in contact with the inner wall of the reinforced pipe pile.

6. A prestressed pipe pile reinforcement process according to any one of claims 1 to 3, characterized in that: In S7, the standing time is 24 hours to 72 hours, and the curing time is 7 days to 14 days.

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