Construction method for improving stiff composite pile under complex geological conditions

Abstract

The invention relates to a construction method for improving a stiff composite pile under complex geological conditions. The construction method comprises the following steps that construction preparation is conducted; during the first stirring, cement paste is prepared according to requirements, the cement consumption and the water consumption are controlled, the cement paste is sprayed to the pile top position to sink to the pile bottom elevation, and the drill rod sprays the cement and is lifted to the pile top elevation; cement paste is prepared according to requirements during secondary stirring, the cement consumption and the water consumption are controlled, drill rod guniting sinking overall-length re-stirring is carried out to reach the pile bottom elevation, and drill rod guniting stirring and lifting are carried out to reach the pile top elevation; rigid piles are constructed, the prestressed pipe piles are hoisted to the pile positions, centering and straightening are conducted, the perpendicularity of the piles is guaranteed, a pile pressing machine is in place, and the prestressed pipe piles are subjected to pile planting, pile splicing and pile conveying; and quality inspection. The construction quality and efficiency of the stiff composite pile under the complex geological condition can be effectively improved.

Description

Technical Field

[0001] This application relates to the technical field of building construction, and particularly to a construction method for improving rigid composite piles under complex geological conditions. Background Art

[0002] At present, with the continuous development of the construction industry, building engineering projects are gradually approaching saturation, and the geological conditions at the development locations of some projects are relatively complex. In the design of building pile foundations, considering factors such as the surrounding environment, geological conditions, and cost, the selected pile foundation type is the rigid composite pile, and this type of pile is a process of mixing first and then implanting the pile. For rigid composite piles, the advantages are that they are more suitable for soft soil and silty sand layer foundations. Compared with conventional pile types, the squeezing effect can be alleviated in practical applications, and the impact on the surrounding environment can be reduced. At the same time, the construction of rigid composite piles also has good economy.

[0003] At the present stage in practice, due to the relatively thick geological silty sand layer, during the construction process of rigid composite piles, construction problems such as poor forming quality of the mixing piles and difficult pile pressing occur. Technical measures such as adding expansive soil and replacing the static pile press are taken during construction, but the actual problems on site are not solved; moreover, during the construction process, the insufficient stability of the rigid piles in the pile splicing link becomes a prominent problem. Specifically, during the pile splicing process, due to the lack of effective stabilizing measures, the splicing position is prone to deviation, affecting the splicing quality and the stability of the overall structure.

[0004] In view of the above related technologies, it is necessary to propose a construction method for improving rigid composite piles under complex geological conditions to solve one of the above technical problems. Summary of the Invention

[0005] In order to solve one of the above technical problems, this application provides a construction method for improving rigid composite piles under complex geological conditions.

[0006] The construction method for improving rigid composite piles under complex geological conditions provided by this application adopts the following technical solutions: A construction method for improving rigid composite piles under complex geological conditions includes the following steps: Construction preparation: level the construction site, accurately position the construction pile positions using measuring tools to ensure that the pile positions are within the required deviation range; prepare construction materials and construction equipment, and debug them to a good state; Flexible pile construction: The mixer is positioned. The drill pipe starts to spray water and mix while sinking from the ground surface to the pile top elevation. For the first mixing, the cement slurry is prepared as required, with the water-cement ratio controlled between 1.0 and 1.2. The cement dosage and water dosage are controlled. When reaching the pile top position, start to spray cement slurry and sink to the pile bottom elevation, with the speed controlled within 1.0 m / min. The drill pipe sprays the slurry and rises to the pile top elevation, with the speed controlled at 2.0 m / min. For the second mixing, the cement slurry is prepared as required, with the water-cement ratio between 0.8 and 1.0. The cement dosage and water dosage are controlled. The drill pipe sprays the slurry and sinks for full-length re-mixing to the pile bottom elevation, with the speed controlled within 1.5 m / min. The drill pipe sprays the slurry and mixes while rising to the pile top elevation, with the speed controlled within 2.0 m / min. Rigid pile construction: Hoist the prestressed pipe pile to the pile position, carry out centering and alignment to ensure the verticality of the pile. The pile press is positioned. Carry out pile driving, pile splicing and pile feeding for the prestressed pipe pile. The completion interval time is controlled within 90 min to prevent the initial setting of the cement soil. During the pile splicing process of the prestressed pipe pile, welding or mechanical connection methods are adopted, and the stability of the pile splicing is ensured by setting a stabilizing mechanism to avoid position deviation at the butt joint during welding or mechanical connection. Quality inspection: Carry out pile integrity detection and bearing capacity detection to make the construction meet the design requirements.

[0007] By adopting the above technical solutions, the construction quality and efficiency of the stiff composite pile under complex geological conditions can be effectively improved. Specifically, through the precise leveling and measurement positioning of the construction site, combined with the step-by-step construction technology of flexible piles and rigid piles, the stability and bearing capacity of the pile body under different geological conditions are ensured. Especially in the construction of flexible piles, by precisely controlling the water-cement ratio and mixing speed of the cement slurry, the strength and uniformity of the cement soil are improved. In the construction of rigid piles, by setting a stabilizing mechanism, the position deviation during the pile splicing process is effectively avoided, and the reliability of the pile body connection is enhanced. In addition, the strict quality inspection process further guarantees the overall performance of the construction and significantly reduces the construction risk.

[0008] Optionally, in the construction of the flexible pile, during the first mixing, the cement dosage is increased by 10% - 20% compared with the conventional dosage, and the water dosage is correspondingly reduced by 5% - 10% to improve the strength and stability of the cement soil. During the second mixing, the cement dosage is the same as that in the first mixing, and the water dosage is further reduced by 3% - 5% to ensure the uniformity and strength of the cement soil.

[0009] By adopting the above technical solutions, during the construction process of the flexible pile, through the precise control of the dosages of cement and water, not only the strength and stability of the cement soil are improved, but also the uniformity of the cement soil is optimized; specifically, increasing the cement dosage and reducing the water dosage during the first mixing can effectively enhance the early strength and compressive performance of the cement soil; further reducing the water dosage during the second mixing ensures that the internal structure of the cement soil is denser, thereby improving the overall construction quality and extending the service life of the pile body.

[0010] Optionally, during the construction of the rigid pile, the pile driving speed of the prestressed pipe pile is controlled within 0.5 m / min to 0.8 m / min. When splicing the piles, welded connection is adopted, the welding current is controlled within 180 A to 220 A, the welding voltage is controlled within 20 V to 25 V, and the welding speed is controlled within 0.8 m / min to 1.2 m / min to ensure the welding quality and connection strength.

[0011] By adopting the above technical solutions, precisely controlling the pile driving speed and welding parameters of the prestressed pipe pile can effectively reduce the quality problems caused by excessive speed or unstable connection during the construction process; at the same time, by setting reasonable ranges for the welding current, voltage, and speed, the heat input during the welding process is ensured to be stable, avoiding welding deformation and stress concentration, thereby significantly enhancing the structural strength and durability of the connection of the prestressed pipe pile.

[0012] Optionally, during the construction preparation, the requirement for the flatness of the construction site is that the height difference within each square meter is controlled within 5 mm, the pile position deviation of the surveying and setting out is controlled within 5 mm, and the debugging of the construction equipment includes the calibration of the verticality of the mixing pile rig, and the verticality deviation is controlled within 0.5% to ensure the accuracy of the construction and the verticality of the subsequent pile body, and improve the construction quality and efficiency.

[0013] By adopting the above technical solutions, the refinement level during the construction preparation stage can be significantly improved, ensuring the flatness of the construction site and the accuracy of the pile position positioning, and effectively reducing the construction errors caused by insufficient preliminary preparation; at the same time, through the strict calibration of the verticality of the mixing pile rig, the verticality requirement of the subsequent pile body construction is further guaranteed, thereby improving the overall construction quality and efficiency and providing a reliable guarantee basis for the pile foundation construction under complex geological conditions.

[0014] Optionally, the stabilizing mechanism includes a stabilizing seat arranged at the construction surface corresponding to the pile position, a stabilizing ring arranged on the stabilizing seat, a plurality of adjusting tracks, a sliding seat, and a supporting frame. The plurality of adjusting tracks are arranged in a circular pattern on the top of the stabilizing ring, and the plurality of adjusting tracks are symmetrically arranged in pairs. The sliding seat is slidably connected to the adjusting track, and the supporting frame is arranged on the top of the sliding seat. The supporting frame abuts against the outside of the prestressed pipe pile and is used for stabilizing the prestressed pipe pile during the welded connection.

[0015] By adopting the above technical solution, the setting of the stabilizing mechanism can effectively improve the stability of the prestressed pipe pile during the welding connection process; specifically, the design of the fixed cooperation of the stabilizing seat with the construction surface, the stabilizing ring and the adjusting track enables the abutting frame to accurately adjust its position and firmly abut against the outside of the prestressed pipe pile, thereby avoiding the offset of the pipe pile caused by external forces during the welding process; this design not only improves the convenience of the welding operation, but also significantly enhances the overall structural strength and reliability of the pile connection.

[0016] Optionally, an arc-shaped groove is arranged at the front end of the abutting frame close to the outside of the prestressed pipe pile, the inner wall of the arc-shaped groove abuts against the outside of the prestressed pipe pile, and fitting pieces are vertically arranged at the upper and lower ends of the abutting frame corresponding to the notch of the arc-shaped groove for expanding the contact surface between the abutting frame and the outside of the prestressed pipe pile.

[0017] By adopting the above technical solution, the setting of the arc-shaped groove and the fitting pieces effectively increases the contact area between the abutting frame and the prestressed pipe pile, thereby improving the force uniformity between the two, reducing the phenomenon of local stress concentration, further enhancing the stability of the prestressed pipe pile during the welding process, and reducing the deformation risk caused by uneven force.

[0018] Optionally, rubber pads are arranged on the inner wall of the arc-shaped groove and the inner side of the fitting piece, and the rubber pads are used to increase the frictional force between the inner wall of the arc-shaped groove and the inner side of the fitting piece and the outside of the prestressed pipe pile.

[0019] By adopting the above technical solution, the setting of the rubber pads can effectively increase the frictional force between the inner wall of the arc-shaped groove and the inner side of the fitting piece and the outside of the prestressed pipe pile, thereby improving the stabilizing effect of the abutting frame on the prestressed pipe pile, preventing the prestressed pipe pile from shifting in position during the welding process, and ensuring the accuracy and stability of the connection.

[0020] Optionally, driving motors are arranged on the outside of the stabilizing ring and corresponding to both sides of the sliding seat, driving gears are arranged at the output ends of the driving motors, racks are arranged on both sides of the sliding seat, and the driving gears are meshed with the racks for adjusting the position of the sliding seat on the adjusting track.

[0021] By adopting the above technical solution, the driving motor drives the driving gear to rotate, and the driving gear is meshed with the rack to achieve precise position adjustment of the sliding seat on the adjusting track; this solution can improve the position adjustment accuracy of the sliding seat, thereby ensuring the stabilizing effect of the abutting frame on the prestressed pipe pile, further enhancing the stability during the welding connection, and reducing the risk of position offset during the welding process.

[0022] Optionally, it further includes a lifting mechanism. The lifting mechanism includes lifting cylinders symmetrically arranged in pairs on one of the sliding seats. A bearing block is arranged at the output end of the lifting cylinder, and the top of the bearing block is connected to the rear end of the bottom of the abutting frame, so as to realize the staggered abutment of the outer part of the prestressed pipe pile at different heights by several abutting frames.

[0023] By adopting the above technical solution, the setting of the lifting mechanism enables the abutting frame to be flexibly adjusted in height, so as to adapt to prestressed pipe piles with different diameters or shapes, and ensure the stability of the prestressed pipe pile during the welding process. This staggered abutting method not only improves the versatility of the device, but also effectively disperses the external force received by the prestressed pipe pile, avoiding problems such as welding deformation or connection failure caused by uneven force, and further improving the construction quality and efficiency.

[0024] Optionally, teeth are fixedly connected to the four peripheries of the bottom of the stabilizing seat, and the teeth are used to stabilize the stabilizing seat at the construction position.

[0025] By adopting the above technical solution, the setting of the teeth effectively enhances the friction between the stabilizing seat and the construction ground, ensures the stability of the stabilizing seat under complex geological conditions, and avoids structural deviation caused by uneven or soft ground, thus providing a reliable support foundation for the precise construction of subsequent prestressed pipe piles.

[0026] In summary, the present application includes at least one of the following beneficial technical effects: 1. By precisely controlling the flatness of the construction site and the accuracy of measurement and setting out in the construction preparation stage, and carefully debugging the equipment, the preparation quality in the early stage of construction is significantly improved, providing a high-precision basic guarantee for subsequent construction; 2. In the construction of flexible piles, the two-time mixing process is adopted, and the cement dosage and water-cement ratio are adjusted respectively, ensuring the gradual increase and uniformity of the strength of the cement soil, and effectively enhancing the adaptability of the flexible piles under complex geological conditions; 3. In the construction of rigid piles, a stabilizing mechanism and strict time control measures are introduced, which not only ensure the stability of the prestressed pipe pile during the pile driving and pile connection process, but also avoid the initial setting problem of the cement soil caused by too long construction interval, thus greatly improving the overall construction quality and bearing performance of the stiff composite pile. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic flow chart of a construction method of an improved stiff composite pile under complex geological conditions in the present application.

[0028] Figure 2 It is a process diagram of the construction of flexible piles in a construction method of an improved stiff composite pile under complex geological conditions in the present application.

[0029] Figure 3It is a three-dimensional view of a stabilizing mechanism of a construction method for improved stiff composite piles under complex geological conditions in this application.

[0030] Figure 4 It is Figure 3 front view of (welded state of prestressed pipe pile).

[0031] In the figure: 1. Stabilizing mechanism; 2. Stabilizing base; 21. Locking teeth; 3. Stabilizing ring; 31. Driving motor; 32. Driving gear; 4. Adjusting track; 5. Sliding seat; 51. Rack; 6. Supporting frame; 61. Arc groove; 62. Fitting piece; 63. Rubber pad; 7. Lifting mechanism; 71. Lifting cylinder; 72. Bearing block. Specific implementation manner

[0032] The following further elaborates on this application in conjunction with the attached drawings Figures 1 - 4 for a more detailed description.

[0033] Example 1, referring to Figure 1 and Figure 2 , the embodiment of this application discloses a construction method for improved stiff composite piles under complex geological conditions, including the following steps: Construction preparation: Level the construction site, accurately locate the construction pile position using measuring tools to ensure that the pile position is within the required deviation range; prepare construction materials and construction equipment and debug them to a good state; Flexible pile construction: The mixer is in place, and the drill pipe starts to spray water and stir and sink from the ground to the pile top elevation. For the first stirring, prepare the cement slurry as required, control the water-cement ratio between 1.0 and 1.2, and control the cement dosage and water dosage. When reaching the pile top position, start spraying cement slurry and sink to the pile bottom elevation, with the speed controlled within 1.0 m / min. The drill pipe sprays slurry and rises to the pile top elevation, with the speed controlled at 2.0 m / min; for the second stirring, prepare the cement slurry as required, with the water-cement ratio between 0.8 and 1.0, control the cement dosage and water dosage, the drill pipe sprays slurry and sinks for full-length re-stirring to the pile bottom elevation, with the speed controlled within 1.5 m / min, and the drill pipe sprays slurry and stirs and rises to the pile top elevation, with the speed controlled within 2.0 m / min; Rigid pile construction: Lift the prestressed pipe pile to the pile position, align and straighten it to ensure the verticality of the pile. The pile press is in place, and the prestressed pipe pile is planted, spliced, and driven, and the completion interval time is controlled within 90 min to prevent the initial setting of the cement soil; during the splicing process of the prestressed pipe pile, welding or mechanical connection methods are adopted, and the stability of the splicing is ensured by setting a stabilizing mechanism to avoid position deviation at the joint during welding or mechanical connection; Quality inspection: Conduct pile integrity detection and bearing capacity detection to ensure that the construction meets the design requirements.

[0034] This application can effectively improve the construction quality and efficiency of stiff composite piles under complex geological conditions. Specifically, through the precise leveling and measurement positioning of the construction site, combined with the step-by-step construction technology of flexible piles and rigid piles, the stability and bearing capacity of the pile body under different geological conditions are ensured. Especially in the construction of flexible piles, by precisely controlling the water-cement ratio and mixing speed of the cement slurry, the strength and uniformity of the cement soil are improved. In the construction of rigid piles, by setting up a stabilizing mechanism, the position deviation during the pile connection process is effectively avoided, and the reliability of the pile body connection is enhanced. In addition, the strict quality inspection process further guarantees the overall performance of the construction and significantly reduces the construction risk.

[0035] In this embodiment, more specifically, during the construction of flexible piles, during the first mixing, the cement dosage is increased by 10% - 20% compared to the conventional dosage, and the water dosage is correspondingly reduced by 5% - 10% to improve the strength and stability of the cement soil. During the second mixing, the cement dosage is the same as that of the first mixing, and the water dosage is further reduced by 3% - 5% to ensure the uniformity and strength of the cement soil. During the construction process of flexible piles, through the precise control of the cement and water dosages, not only the strength and stability of the cement soil are improved, but also the uniformity of the cement soil is optimized. Specifically, increasing the cement dosage and reducing the water dosage during the first mixing can effectively enhance the early strength and compressive performance of the cement soil. Further reducing the water dosage during the second mixing ensures that the internal structure of the cement soil is denser, thereby improving the overall construction quality and extending the service life of the pile body.

[0036] In this embodiment, more specifically, during the construction of rigid piles, the pile driving speed of the prestressed pipe pile is controlled at 0.5m / min - 0.8m / min. When connecting the piles, welding connection is adopted, the welding current is controlled at 180A - 220A, the welding voltage is controlled at 20V - 25V, and the welding speed is controlled at 0.8m / min - 1.2m / min to ensure the welding quality and connection strength. Precisely controlling the pile driving speed and welding parameters of the prestressed pipe pile can effectively reduce the quality problems caused by too fast speed or unstable connection during the construction process. At the same time, by setting the reasonable ranges of the welding current, voltage, and speed, the heat input during the welding process is ensured to be stable, avoiding welding deformation and stress concentration, thereby significantly enhancing the structural strength and durability of the connection part of the prestressed pipe pile.

[0037] In this embodiment, more specifically, during construction preparation, the requirement for the flatness of the construction site is that the height difference within each square meter is controlled within 5 mm, the deviation of the pile positions in surveying and setting out is controlled within 5 mm, and the debugging of the construction equipment includes the calibration of the verticality of the mixing pile rig, with the verticality deviation controlled within 0.5%, to ensure the accuracy of construction and the verticality of the subsequent pile bodies, improve the construction quality and efficiency, significantly enhance the refinement level in the construction preparation stage, ensure the flatness of the construction site and the accuracy of pile position positioning, and effectively reduce construction errors caused by insufficient preliminary preparation; at the same time, through the strict calibration of the verticality of the mixing pile rig, the verticality requirement for the subsequent pile body construction is further guaranteed, thereby improving the overall construction quality and efficiency and providing a reliable guarantee basis for pile foundation construction under complex geological conditions.

[0038] Embodiment 2, referring to Figure 3 and Figure 4 , the difference between this embodiment and Embodiment 1 is that: the stabilizing mechanism 1 includes a stabilizing seat 2 provided at the construction surface corresponding to the pile position, a stabilizing ring 3 provided on the stabilizing seat 2, a plurality of adjusting tracks 4, a sliding seat 5 and a supporting frame 6. The plurality of adjusting tracks 4 are arranged in a circular pattern on the top of the stabilizing ring 3, and the plurality of adjusting tracks 4 are symmetrically arranged in pairs. The sliding seat 5 is slidably connected to the adjusting track 4, and the supporting frame 6 is provided on the top of the sliding seat 5. The supporting frame 6 abuts against the outside of the prestressed pipe pile and is used for stabilizing the prestressed pipe pile during welding connection. The setting of the stabilizing mechanism 1 can effectively improve the stability of the prestressed pipe pile during the welding connection process; specifically, the fixed cooperation between the stabilizing seat 2 and the construction surface and the design of the stabilizing ring 3 and the adjusting tracks 4 enable the supporting frame 6 to accurately adjust its position and firmly abut against the outside of the prestressed pipe pile, thereby avoiding the deviation of the pipe pile caused by external forces during the welding process; this design not only improves the convenience of the welding operation but also significantly enhances the overall structural strength and reliability of the pile joint.

[0039] In this embodiment, more specifically, an arc-shaped groove 61 is provided at the front end of the supporting frame 6 close to the outside of the prestressed pipe pile, and the inner wall of the arc-shaped groove 61 abuts against the outside of the prestressed pipe pile. Corresponding to the notch of the arc-shaped groove 61, fitting pieces 62 are vertically provided at the upper and lower ends of the supporting frame 6 for expanding the contact surface between the supporting frame 6 and the outside of the prestressed pipe pile. The setting of the arc-shaped groove 61 and the fitting pieces 62 effectively increases the contact area between the supporting frame 6 and the prestressed pipe pile, thereby enhancing the force uniformity between the two, reducing the local stress concentration phenomenon, further improving the stability of the prestressed pipe pile during the welding process, and reducing the deformation risk caused by uneven force.

[0040] In this embodiment, more specifically, rubber pads 63 are provided on the inner wall of the arc-shaped groove 61 and the inner side of the fitting piece 62. The rubber pads 63 are used to increase the external friction between the inner wall of the arc-shaped groove 61 and the inner side of the fitting piece 62 and the prestressed pipe pile. The setting of the rubber pads 63 can effectively increase the friction between the inner wall of the arc-shaped groove 61 and the inner side of the fitting piece 62 and the outside of the prestressed pipe pile, thereby improving the stabilizing effect of the holding frame 6 on the prestressed pipe pile, preventing the prestressed pipe pile from shifting in position during welding, and ensuring the accuracy and stability of the connection.

[0041] In this embodiment, more specifically, driving motors 31 are provided on the outside of the stabilizing ring 3 and corresponding to both sides of the sliding seat 5. The output end of the driving motor 31 is provided with driving gears 32. Rack bars 51 are provided on both sides of the sliding seat 5. The driving gears 32 and the rack bars 51 are meshed with each other for adjusting the position of the sliding seat 5 on the adjusting track 4. The driving motor 31 drives the driving gears 32 to rotate, and the driving gears 32 and the rack bars 51 are meshed with each other to achieve precise position adjustment of the sliding seat 5 on the adjusting track 4. This solution can improve the position adjustment accuracy of the sliding seat 5, thereby ensuring the stabilizing effect of the holding frame 6 on the prestressed pipe pile, further enhancing the stability during welding connection, and reducing the risk of position deviation during the welding process.

[0042] In this embodiment, more specifically, a lifting mechanism 7 is further included. The lifting mechanism 7 includes lifting cylinders 71 provided on one group of the sliding seats 5 symmetrically arranged in pairs. The output end of the lifting cylinder 71 is provided with a bearing block 72. The top of the bearing block 72 is connected to the rear end of the bottom of the holding frame 6, for achieving staggered height holding of the outer part of the prestressed pipe pile by several holding frames 6. The setting of the lifting mechanism 7 enables the holding frame 6 to be flexibly adjusted in height, so as to adapt to prestressed pipe piles of different diameters or shapes, and ensure the stability of the prestressed pipe pile during welding. This staggered height holding method not only improves the versatility of the device, but also can effectively disperse the external force received by the prestressed pipe pile, avoiding problems such as welding deformation or connection failure caused by uneven stress, and further improving the construction quality and efficiency.

[0043] In this embodiment, more specifically, teeth 21 are fixedly connected to the four peripheries of the bottom of the stabilizing seat 2. The teeth 21 are used for stabilizing the stabilizing seat 2 at the construction position. The setting of the teeth 21 effectively enhances the friction between the stabilizing seat 2 and the construction ground, ensures the stability of the stabilizing seat 2 under complex geological conditions, and avoids structural deviation caused by uneven or soft ground, thereby providing a reliable support foundation for the precise construction of the subsequent prestressed pipe pile.

[0044] The implementation principle of the second embodiment of this application is as follows: By setting up the stabilizing mechanism 1, the problem of possible position deviation during pile splicing in rigid pile construction is effectively solved. Specifically, the stabilizing mechanism 1 can flexibly adjust the abutting position through the cooperation of the adjusting track 4, the sliding seat 5 and the abutting frame 6 to adapt to prestressed pipe piles with different diameters. At the same time, through the meshing transmission of the driving motor 31 and the rack 51, precise position control is achieved. The design of the teeth 21 at the bottom of the stabilizing seat 2 enhances the stability of the entire mechanism and prevents displacement during construction. This solution significantly improves the precision and efficiency of rigid pile construction and provides strong guarantee for the construction of stiff composite piles under complex geological conditions.

[0045] The above are all the preferred embodiments of this application, and the protection scope of this application is not limited accordingly. Therefore, all equivalent changes made according to the structure, shape and principle of this application shall be covered within the protection scope of this application.

Claims

1. A construction method for improving rigid composite piles under complex geological conditions, characterized in that: The following steps are involved: Preparation for construction: level the construction site, use measuring tools to accurately locate the construction pile position, and ensure that the pile position is within the required deviation range; prepare construction materials and equipment, and debug them to a good condition; During the construction of flexible piles, the mixer is in place, and the drill rod starts to spray water from the ground and mixes and sinks to the pile top elevation. The cement slurry is prepared as required for the first mixing, and the water-cement ratio is controlled between 1.0 and 1.

2. The cement and water amounts are controlled. When the cement slurry reaches the pile top, it starts to spray and sink to the pile bottom elevation. The speed is controlled within 1.0 m / min. The drill rod is sprayed and lifted to the pile top elevation. The speed is controlled within 2.0 m / min. The cement slurry is prepared as required for the second mixing, and the water-cement ratio is between 0.8 and 1.

0. The cement and water amounts are controlled. The drill rod is sprayed and sunk along the entire length and mixed again to the pile bottom elevation. The speed is controlled within 1.5 m / min. The drill rod is sprayed and mixed and lifted to the pile top elevation. The speed is controlled within 2.0 m / min. In rigid pile construction, the prestressed pipe piles are hoisted to the pile position, and the piles are aligned and straightened to ensure the verticality of the piles. The pile driver is in place, and the prestressed pipe piles are planted, connected and delivered. The completion interval is controlled within 90 minutes to prevent the initial setting of cement soil. In the process of connecting the prestressed pipe piles, welding or mechanical connection is adopted, and a stabilizing mechanism is set to ensure the stability of the connected piles to avoid position displacement at the joint during welding or mechanical connection. Quality inspection includes pile integrity testing and bearing capacity testing to ensure that the construction meets the design requirements.

2. The construction method of improved composite piles under complex geological conditions according to claim 1, characterized in that: In the flexible pile construction, during the first mixing, the amount of cement is increased by 10% to 20% compared with the conventional amount, and the amount of water is correspondingly reduced by 5% to 10% to improve the strength and stability of the cement soil; during the second mixing, the amount of cement is the same as the first mixing, and the amount of water is further reduced by 3% to 5% to ensure the uniformity and strength of the cement soil.

3. The construction method of improved composite piles under complex geological conditions according to claim 1, characterized in that: In the rigid pile construction, the planting speed of the prestressed pipe piles is controlled at 0.5m / min~0.8m / min, welding is used for connecting the piles, the welding current is controlled at 180A~220A, the welding voltage is controlled at 20V~25V, and the welding speed is controlled at 0.8m / min~1.2m / min to ensure the welding quality and connection strength.

4. The construction method of improved rigid composite piles under complex geological conditions according to claim 1, characterized in that: During the construction preparation, the flatness requirement for the construction site is that the height difference per square meter is controlled within 5mm, the pile position deviation of the measurement and layout is controlled within 5mm, and the commissioning of the construction equipment includes the verticality calibration of the pile mixing machine, and the verticality deviation is controlled within 0.5%, so as to ensure the accuracy of the construction and the verticality of the subsequent pile body, and improve the construction quality and efficiency.

5. The construction method of improved rigid composite piles under complex geological conditions according to claim 1, characterized in that: The stabilizing mechanism (1) comprises a stabilizing seat (2) arranged at a construction surface corresponding to the pile position, a stabilizing ring (3) arranged on the stabilizing seat (2), a plurality of adjusting rails (4), a sliding seat (5) and a supporting frame (6), wherein the plurality of adjusting rails (4) are arranged in a circular shape on the top of the stabilizing ring (3), and the plurality of adjusting rails (4) are arranged symmetrically in pairs, the sliding seat (5) is slidably connected to the adjusting rails (4), and the supporting frame (6) is arranged on the top of the sliding seat (5), and the supporting frame (6) supports the outside of the prestressed pipe pile and is used for stabilizing the prestressed pipe pile when it is welded.

6. The construction method of improved composite piles under complex geological conditions according to claim 5, characterized in that: The front end of the supporting frame (6) is provided with an arc-shaped groove (61) near the outside of the prestressed pipe pile, and the inner wall of the arc-shaped groove (61) abuts against the outside of the prestressed pipe pile. The upper and lower ends of the supporting frame (6) are vertically provided with fitting pieces (62) corresponding to the notches of the arc-shaped groove (61) for expanding the contact surface between the supporting frame (6) and the outside of the prestressed pipe pile.

7. The construction method of improved composite piles under complex geological conditions according to claim 6, characterized in that: The inner wall of the arc-shaped groove (61) and the inner side of the fitting sheet (62) are both provided with rubber pads (63), and the rubber pads (63) are used to increase the external friction between the inner wall of the arc-shaped groove (61) and the inner side of the fitting sheet (62) and the prestressed pipe pile.

8. The construction method of improved rigid composite piles under complex geological conditions according to claim 5, characterized in that: A driving motor (31) is arranged outside the stabilizing ring (3) and on both sides corresponding to the sliding seat (5); a driving gear (32) is arranged at the output end of the driving motor (31); racks (51) are arranged on both sides of the sliding seat (5); the driving gear (32) and the racks (51) are meshed with each other and are used for adjusting the position of the sliding seat (5) on the adjustment track (4).

9. The construction method of improved composite piles under complex geological conditions according to claim 5, characterized in that: It also includes a lifting mechanism (7), the lifting mechanism (7) including a group of lifting cylinders (71) symmetrically arranged in pairs on the sliding seat (5), the output end of the lifting cylinder (71) is provided with a bearing block (72), the top of the bearing block (72) is connected to the bottom rear end of the supporting frame (6), and is used to achieve a plurality of the supporting frames (6) supporting the outside of the prestressed pipe pile at staggered heights.

10. The construction method of improved composite piles under complex geological conditions according to claim 5, characterized in that: The bottom of the stabilizing seat (2) is fixedly connected with latch teeth (21) on all sides, and the latch teeth (21) are used to stabilize the stabilizing seat (2) at the construction site.

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