Efficient pile-forming construction method for large-diameter pile foundation in complex geology

Abstract

The invention relates to the technical field of building construction, in particular to a complex geology large-diameter pile foundation efficient pile forming construction method which comprises the following steps that S1, early-stage investigation and scheme adaptation are conducted; s2, orifice reinforcement and precise lofting are carried out; s3, layered hole forming and dynamic wall protection; s4, composite hole cleaning and sediment prevention and control; s5, reinforcement cage prefabrication and speediness; s6, continuous pouring and quality monitoring are carried out; s7, carrying out environmental protection treatment and safety monitoring; and S8, after the pile is formed, the pile foundation quality is detected through a low strain method and a static load test. According to the method, full complex stratum adaptation and multi-procedure collaborative operation can be achieved, the construction efficiency and quality are improved, and the environmental protection and safety risks are reduced.

Description

Technical Field

[0001] This invention relates to an efficient pile-forming construction method for large-diameter pile foundations in complex geological conditions, and particularly to an efficient pile-forming construction method for large-diameter pile foundations in complex geological conditions, belonging to the field of building construction technology. Background Technology

[0002] With the large-scale construction of major infrastructure projects such as transportation hubs, super high-rise buildings, and offshore wind power platforms in my country, project site selection is gradually extending to complex geological areas such as mountainous areas, coastal areas, and river valley terraces. These areas generally feature uneven soil distribution, high sand and gravel content, large undulations in weathered rock layers, abundant and high-pressure groundwater, and some areas are also accompanied by adverse geological conditions such as quicksand, silty clay, and karst cavities, posing severe challenges to pile foundation construction. Large-diameter piles, with their strong bearing capacity and excellent anti-settlement performance, have become the core load-bearing foundation form for such major projects, and their construction quality and efficiency directly determine the overall project schedule, cost, and structural safety and stability.

[0003] Currently, the industry has developed several mature technical solutions for the construction of large-diameter pile foundations under complex geological conditions. These mainly include bored cast-in-place piles, precast pipe pile pre-drilling and driving, and impact drilling rock-embedded piles. Among them, rotary drilling mud wall protection technology is widely used in clay, silt, and moderately weathered rock strata due to its flexibility and adaptability; reverse circulation drilling technology is often used for ultra-deep, rock-embedded pile foundation construction due to its high slag removal efficiency; full casing full rotation technology is widely used in adverse strata such as quicksand and silt due to its ability to effectively control the risk of borehole collapse; and precast pipe pile pre-drilling and driving technology is suitable for batch pile construction in some sandy and cohesive soil strata due to its fast construction speed and controllable quality.

[0004] However, in actual complex geological construction processes, existing technical solutions still have many problems that urgently need to be solved, specifically as follows: 1. Low drilling efficiency and poor stability; a single drilling process is difficult to adapt to construction in all formations; drilling in gravel layers is slow, and boreholes are prone to collapse in quicksand layers. 2. Difficult and inaccurate rock-embedded construction; the verticality deviation of percussion drilling in rock embedding is large; reverse circulation drilling is prone to uncontrolled drilling pressure and drill bit wear. 3. Poor sediment control; traditional hole cleaning processes are difficult to remove large-diameter sediment, which easily leads to sediment back accumulation and affects the quality of pile foundations. 4. Poor equipment coordination; discontinuous construction process; long equipment downtime; long single-pile construction cycle. 5. Insufficient environmental and safety risk management; high difficulty in waste slurry treatment; lack of real-time monitoring and emergency response measures; high probability of safety accidents.

[0005] Therefore, there is an urgent need for an efficient pile-forming construction method for large-diameter pile foundations in complex geological conditions to solve the aforementioned problems. Summary of the Invention

[0006] The purpose of this invention is to provide an efficient pile-forming construction method for large-diameter pile foundations in complex geological conditions, addressing the problems of low drilling efficiency, poor stability, insufficient rock embedding accuracy, poor sediment control, poor equipment synergy, and high environmental and safety risks in the construction of large-diameter pile foundations in complex geological conditions by existing technologies.

[0007] To achieve the above objectives, the main technical solution adopted by this invention includes: a method for efficient pile construction of large-diameter pile foundations in complex geological conditions, comprising the following steps: S1: Preliminary investigation and scheme adaptation: Detailed geological data of the construction area are obtained by combining drone aerial photography with geological drilling; based on the geological data, drilling technology, equipment models and mud parameters are matched to formulate a construction scheme of layered technology + equipment coordination; S2: Orifice reinforcement and precise layout: Pour concrete orifice platform, use total station + GPS dual-mode positioning system for layout with an error of 3cm, and install guide frame; S3: Layered drilling and dynamic wall protection: The upper quicksand / silt layer is constructed using a full-casing rotary drilling rig + rotary drilling; the middle sand and gravel layer is constructed using a small-diameter pilot hole + staged hole expansion process + high-viscosity modified mud wall protection; the lower weathered rock layer / bedrock is constructed using a fully hydraulic rotary reverse circulation drilling rig + roller cutter bit. S4: Composite hole cleaning and sediment control: After hole formation, reverse circulation is used for hole cleaning once. After the steel cage is lowered, air lift reverse circulation + high pressure jet composite hole cleaning is used. The sediment thickness is 30mm. Concrete is poured within 30 minutes after hole cleaning. S5: Reinforcing cage prefabrication and rapid hoisting: The reinforcing cage is prefabricated in sections in the factory, with mechanical connection joints, and hoisting is carried out by two machines in 40 minutes. S6: Continuous pouring and quality monitoring: underwater concrete pouring using the tremie pipe method, with the initial grouting pipe buried at 1.2m, the tremie pipe burial depth controlled at 2-6m, and continuous pouring without interruption; S7: Environmental protection and safety monitoring: Waste slurry is purified and reused, and waste residue is centrally transported off-site; real-time monitoring equipment is installed, and emergency measures are activated in case of abnormalities; S8: After pile completion, the quality of the pile foundation is tested using the low-strain method and static load test.

[0008] Preferably, in step S1, the geological data includes the distribution range, thickness, and physical and mechanical parameters of the upper quicksand / silt layer, the middle sand and gravel layer, and the lower weathered rock layer / bedrock. The equipment model matching is based on the hardness, particle size, and water pressure parameters of each geological layer.

[0009] Preferably, in step S2, the concrete orifice platform is made of C30 concrete with dimensions of 2m x 2m x 0.5m, and the guide frame is formed by welding steel sections with a verticality deviation of 0.5%.

[0010] Preferably, in step S3, during the construction of the upper quicksand / silt layer, the casing of the full-casing rotary drilling rig is lowered to 0.5m below the top surface of the gravel layer, and the drilling speed of the rotary drilling rig is controlled at 1.2-1.5m / h.

[0011] Preferably, in step S3, when constructing the middle sand and gravel layer, the specific steps of the small-diameter pilot hole + staged hole expansion process are as follows: first, use an 800mm drill bit to drill the hole, and then gradually expand the hole to the designed pile diameter; the specific gravity of the high-viscosity modified mud is controlled at 1.25-1.3, and the sand content is <5%.

[0012] Preferably, in step S3, during the construction of the lower weathered rock layer / bedrock, the drilling pressure of the fully hydraulic rotary reverse circulation drilling rig is dynamically adjusted according to the rock layer hardness: 25-35MPa for soft rock and 60-80MPa for hard rock; the rotation speed is adjusted within the range of 8-12rpm for soft rock and 5-8rpm for hard rock, and the slag is discharged by air lift reverse circulation.

[0013] Preferably, in step S4, the specific implementation of the air-lift reverse circulation + high-pressure jet composite hole cleaning process is as follows: the high-pressure jet device set at the bottom of the hole impacts and crushes the large-diameter sediment, and the air-lift reverse circulation system is simultaneously started to forcefully discharge the crushed sediment to the outside of the hole.

[0014] Preferably, in step S5, the mechanical connection joints of the reinforcing cage are staggered by a distance of 35d, and the dual-machine collaborative hoisting adopts a lifting method in which the main crane and the auxiliary crane cooperate. During the lowering of the reinforcing cage, the guide frame ensures that it is centered with a deviation of 5cm.

[0015] Preferably, in step S6, the diameter of the conduit is 300mm, the concrete pouring speed is controlled at 2.5-3m / h, the over-pouring height after pouring is 0.8-1.0m, and the over-pouring part is subsequently removed by chiseling away the laitance to ensure the quality of the pile top.

[0016] Preferably, in step S7, the real-time monitoring equipment includes a borehole settlement monitor, a mud performance monitor, and a verticality monitor; the abnormal monitoring criteria are: borehole settlement of 5cm, mud sand content >8%, or verticality deviation >3cm, and the corresponding emergency measures include adding casing, adjusting mud parameters, or stopping the machine for backfilling.

[0017] The present invention has at least the following beneficial effects: 1. Improved drilling efficiency and stability: By combining layered technology, full casing wall protection, and modified mud, the system adapts to the different characteristics of complex strata. The risk of hole collapse in the upper quicksand layer is reduced by more than 90%, the drilling speed in the middle gravel layer is increased by 40-60%, and the rock penetration efficiency in the lower rock layer is increased by more than 50%. The drilling time for a single pile is shortened to 1.5-2 days, which is 50% more efficient than traditional technology.

[0018] 2. Improve rock embedding accuracy and pile quality: By adopting dynamic drilling pressure + rotation speed adjustment and reverse circulation slag removal technology, the verticality deviation of the pile hole is controlled within 3cm and the rock embedding depth accuracy error is 10cm; the composite hole cleaning process reduces the sediment thickness to 30mm, effectively improving the bearing capacity of the pile end, and the pile foundation quality qualification rate reaches 100%.

[0019] 3. Optimize equipment coordination and process integration: Adopt the collaborative operation of full casing drilling rig + rotary drilling rig + reverse circulation drilling rig, combined with factory prefabrication of steel cages and dual-machine hoisting, to reduce equipment idle time and improve process integration efficiency by 30%; the single pile construction cycle is shortened from the traditional 3-5 days to 1.5-2 days, meeting the schedule requirements of batch construction.

[0020] 4. Reduce environmental and safety risks: The modified mud recycling rate reaches over 85%, waste mud discharge is reduced by 80%, and centralized treatment of waste residue meets environmental protection requirements; the real-time monitoring system enables early warning of risks, reducing the incidence of safety accidents such as borehole collapse and sand inrush by over 95%, ensuring construction safety and personnel safety. Attached Figure Description

[0021] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a process flow diagram of the present invention. Detailed Implementation

[0022] The following will describe in detail the implementation of this application with reference to the accompanying drawings and embodiments, so that the implementation process of how this application uses technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly.

[0023] like Figure 1 As shown in this embodiment, the efficient pile construction method for large-diameter pile foundations in complex geological conditions includes the following steps: S1. Preliminary Exploration and Scheme Adaptation: Using drone aerial photography combined with geological drilling, detailed geological data of the construction area is obtained, clarifying the distribution range, thickness, and physical and mechanical parameters of the upper quicksand / silt layer, the middle sand and gravel layer, and the lower weathered rock / bedrock layer; based on the geological data, the corresponding drilling technology, equipment model, and mud parameters are matched to formulate a construction scheme of layered technology + equipment coordination.

[0024] S2. Hole Reinforcement and Precise Layout: A C30 concrete platform (2m x 2m x 0.5m) is poured at the pile location to enhance the stability of the hole opening; a total station + GPS dual-mode positioning system is used for pile location layout, with the error controlled within 3cm; a guide frame is installed to ensure the stability of the drill rod verticality benchmark during drilling.

[0025] S3. Layered pore formation and dynamic wall protection: S3.1 Upper quicksand / silt layer: Use a full-casing rotary drilling rig to follow the casing wall, with the casing extending 0.5m below the top surface of the sand and gravel layer; simultaneously use rotary drilling to remove soil, with the drilling speed controlled at 1.2-1.5m / h to avoid disturbing the quicksand layer.

[0026] S3.2 Middle gravel layer: Replace the roller cone crusher bit and adopt a small diameter pilot hole + staged reaming process. First, use an 800mm drill bit for pilot hole, and then ream it to the designed pile diameter. During the drilling process, use high viscosity modified mud for wall protection. The mud specific gravity is controlled at 1.25-1.3 and the sand content is <5%. The mud performance is monitored and adjusted in real time through the mud circulation system.

[0027] S3.3 Lower weathered rock layer / bedrock: Switch to a fully hydraulic rotary reverse circulation drilling rig, equipped with a roller drill bit, and dynamically adjust the drilling pressure (25-35MPa for soft rock, 60-80MPa for hard rock) and rotation speed (8-12rpm for soft rock, 5-8rpm for hard rock) according to the hardness of the rock layer; adopt air lift reverse circulation for slag removal to improve rock entry efficiency and slag removal effect.

[0028] S4. Composite Hole Cleaning and Sludge Control: After hole formation, reverse circulation is used for hole cleaning to remove most of the sludge; after the steel cage is lowered, a composite hole cleaning process of air lift reverse circulation + high pressure jet is adopted, and large-diameter sludge is impacted by a high pressure jet device at the bottom of the hole, while reverse circulation is carried out simultaneously; after hole cleaning is completed, the sludge thickness is checked to ensure 30mm; concrete pouring is started within 30 minutes after hole cleaning to avoid sludge back accumulation.

[0029] S5. Prefabrication and rapid hoisting of steel cages: Steel cages are prefabricated in sections in the factory using mechanical connection joints with a staggered distance of 35d (d is the diameter of the steel bar); on site, a dual-crane hoisting system (main crane + auxiliary crane) is used for coordinated hoisting, and the hoisting time is controlled within 40 minutes; during the lowering of the steel cage, a guide frame is used to ensure that it is centered and avoids collision with the hole wall.

[0030] S6. Continuous pouring and quality monitoring: Underwater concrete pouring is carried out using the tremie pipe method with a diameter of 300mm. The initial pouring volume ensures a pipe embedment depth of 1.2m. During the pouring process, an ultrasonic level gauge is used to monitor the concrete surface height in real time and control the tremie pipe embedment depth between 2-6m. The pouring speed is maintained at 2.5-3m / h to ensure continuous and uninterrupted concrete pouring. The over-pouring height is controlled at 0.8-1.0m, and the quality of the pile top is ensured after the laitance is removed.

[0031] S7. Environmental Protection and Safety Monitoring: Waste slurry generated during construction is purified by centrifuge, and the purified slurry is recycled and reused. Waste residue is transported to a designated site. Borehole settlement monitoring instruments, slurry performance monitoring instruments, and verticality monitoring instruments are installed to collect data in real time. When borehole settlement is detected to be 5cm, slurry sand content is >8%, or verticality deviation is >3cm, emergency measures are immediately initiated (such as adding casing, adjusting slurry parameters, and shutting down the machine for backfilling).

[0032] S8. Post-pile testing: The integrity of the pile body is tested using the low-strain method 7 days after pile completion, and the bearing capacity of the pile foundation is tested using a static load test 28 days later to ensure that it meets the design requirements.

[0033] Detailed Implementation: Step 1. Preliminary Investigation and Scheme Adaptation: Aerial photography by drones combined with 12 geological boreholes was used to accurately obtain the distribution parameters of each soil layer; the equipment combination of full casing + rotary drilling + reverse circulation drilling rig was matched, and modified mud parameters (specific gravity 1.25-1.3) were formulated. This can avoid process mismatch caused by inaccurate geological investigation, avoid construction risks in advance, and improve the scheme adaptability by 80%. Step 2. Reinforcement and precise layout of the borehole opening: Pour C30 concrete borehole platform, use total station + GPS positioning, pile position error 2cm; install guide frame; control the settlement of the borehole opening to 2cm to avoid the borehole opening collapse; the pile position deviation is reduced by 40% compared with the traditional process, laying the foundation for the subsequent drilling accuracy.

[0034] Step 3. Layered pore formation and dynamic wall protection: (1) Upper quicksand layer: The casing was advanced to 0.5m below the top surface of the gravel layer, and the soil was removed by rotary drilling at a speed of 1.3m / h. No hole collapse or diameter reduction occurred in the quicksand layer. The hole stability was improved by 95% compared with the traditional mud wall protection process, and the drilling speed was improved by 30%.

[0035] (2) Middle gravel layer: After the 800mm pilot hole is expanded to 2.0m, modified mud is used for circulation wall protection, and the sand content is controlled at 4%; to avoid the problem of severe drill bit wear when drilling in the gravel layer, the service life of the drill bit is extended by 50%; the sand content of the mud is reduced, and the integrity of the hole wall is improved by 60%.

[0036] (3) Lower granite layer: reverse circulation drilling rig + roller drill bit, drilling pressure 70MPa, rotation speed 6rpm, air lift reverse circulation slag removal; rock penetration efficiency reaches 0.8m / h, which is 80% higher than traditional impact drill; excellent slag removal effect, and the amount of rock cuttings remaining at the bottom of the hole is reduced by 70%.

[0037] Step 4. Composite Hole Cleaning and Sediment Control: After the first hole cleaning, a composite hole cleaning method of air lift reverse circulation + high pressure jet is used, and the sediment thickness is measured to be 25mm; pouring is started 25 minutes after hole cleaning; the sediment thickness is reduced by 50% compared with the traditional hole cleaning process, avoiding the problem of sediment back accumulation, and the pile end bearing capacity is increased by more than 20%.

[0038] Step 5. Reinforcing cage hoisting and concrete pouring: The reinforcing cage is prefabricated in the factory, and the hoisting time is 35 minutes with two cranes; the concrete is poured continuously, the tremie pipe is buried at a depth of 3-5m, and the over-pouring is 0.9m; the hoisting time is shortened by 30% to avoid collision with the hole wall during the hoisting of the reinforcing cage; the concrete pouring is uninterrupted, the pile body is free of mud inclusions and broken pile defects, and the pile body integrity qualification rate is 100%.

[0039] Step 6. Environmental Protection and Safety Monitoring: The waste slurry purification and reuse rate is 88%, and the waste residue is transported off-site in a centralized manner; real-time monitoring data shows that the borehole settlement is 3cm and the mud sand content is 4%, with no abnormalities; the waste slurry discharge is reduced by 82%, meeting environmental protection requirements; the safety accident rate is 0, and the safety risk is reduced by 95% compared with the traditional process.

[0040] Step 7. Post-pile inspection: Low-strain tests showed that all piles were Class I piles, and the static load test showed that the bearing capacity reached 1.2 times the design value; the pile quality was excellent, requiring no rework, further saving time and costs.

[0041] III. Comparison of Implementation Results In this embodiment, the construction cycle of a single pile is 1.8 days, which is 55% shorter than the traditional process (4 days); the pass rate of pile quality is 100%, which is 20% higher than the traditional process; the cost of waste slurry treatment is reduced by 75% and there are zero safety accidents, which fully verifies the efficiency, safety and economy of the present invention in the construction of large-diameter pile foundations in complex geology.

[0042] The specification and claims use certain terms to refer to specific components. Those skilled in the art will understand that hardware manufacturers may use different names to refer to the same component. This specification and claims do not distinguish components based on differences in name, but rather on differences in function. The term "inclusion" used throughout the specification and claims is an open-ended term and should be interpreted as including but not limited to. "Generally speaking" refers to the ability of those skilled in the art to solve the technical problem and achieve the basic technical effect within an acceptable margin of error.

[0043] It should be noted that the terms "include," "contain," or any other variations thereof are intended to cover non-exclusive inclusion, such that a product or system that includes a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a product or system. Without further limitations, the inclusion of a defined element by a statement does not exclude the presence of other identical elements in the product or system that includes that element.

[0044] The foregoing description illustrates and describes several preferred embodiments of the present invention. However, as previously stated, it should be understood that the present invention is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the inventive concept described herein through the foregoing teachings or techniques or knowledge in related fields. Any modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present invention should be within the protection scope of the appended claims.

Claims

1. A method for efficient pile construction of large-diameter pile foundations in complex geological conditions, characterized in that: Includes the following steps: S1: Preliminary investigation and scheme adaptation: Detailed geological data of the construction area are obtained by combining drone aerial photography with geological drilling; based on the geological data, drilling technology, equipment models and mud parameters are matched to formulate a construction scheme of layered technology + equipment coordination; S2: Orifice reinforcement and precise layout: Pour concrete orifice platform, use total station + GPS dual-mode positioning system for layout with an error of 3cm, and install guide frame; S3: Layered drilling and dynamic wall protection: The upper quicksand / silt layer is constructed using a full-casing rotary drilling rig + rotary drilling; the middle sand and gravel layer is constructed using a small-diameter pilot hole + staged hole expansion process + high-viscosity modified mud wall protection; the lower weathered rock layer / bedrock is constructed using a fully hydraulic rotary reverse circulation drilling rig + roller cutter bit. S4: Composite hole cleaning and sediment control: After hole formation, reverse circulation is used for hole cleaning once. After the steel cage is lowered, air lift reverse circulation + high pressure jet composite hole cleaning is used. The sediment thickness is 30mm. Concrete is poured within 30 minutes after hole cleaning. S5: Reinforcing cage prefabrication and rapid hoisting: The reinforcing cage is prefabricated in sections in the factory, with mechanical connection joints, and hoisting is carried out by two machines in 40 minutes. S6: Continuous pouring and quality monitoring: underwater concrete pouring using the tremie pipe method, with the initial grouting pipe buried at 1.2m, the tremie pipe burial depth controlled at 2-6m, and continuous pouring without interruption; S7: Environmental protection treatment and safety monitoring: waste slurry is purified and reused, and waste residue is centrally transported off-site; Install real-time monitoring equipment and activate emergency measures in case of abnormalities; S8: After pile completion, the quality of the pile foundation is tested using the low-strain method and static load test.

2. The efficient pile construction method for large-diameter pile foundations in complex geological conditions according to claim 1, characterized in that: In step S1, the geological data includes the distribution range, thickness, and physical and mechanical parameters of the upper quicksand / silt layer, the middle sand and gravel layer, and the lower weathered rock / bedrock layer. The equipment model matching is based on the hardness, particle size, and water pressure parameters of each geological layer.

3. The efficient pile construction method for large-diameter pile foundations in complex geological conditions according to claim 1, characterized in that: In step S2, the concrete orifice platform is made of C30 concrete and has dimensions of 2m x 2m x 0.5m. The guide frame is made of welded steel sections and has a verticality deviation of 0.5%.

4. The efficient pile construction method for large-diameter pile foundations in complex geological conditions according to claim 1, characterized in that: In step S3, during the construction of the upper quicksand / silt layer, the casing of the full-casing rotary drilling rig is lowered to 0.5m below the top surface of the sand and gravel layer, and the drilling speed of the rotary drilling rig is controlled at 1.2-1.5m / h.

5. The efficient pile construction method for large-diameter pile foundations in complex geological conditions according to claim 1, characterized in that: In step S3, when constructing the middle sand and gravel layer, the specific steps of the small-diameter pilot hole + staged hole expansion process are as follows: first, use an 800mm drill bit to drill the hole, and then gradually expand the hole to the designed pile diameter; the specific gravity of the high-viscosity modified mud is controlled at 1.25-1.3, and the sand content is <5%.

6. The efficient pile construction method for large-diameter pile foundations in complex geological conditions according to claim 1, characterized in that: In step S3, during the construction of the lower weathered rock layer / bedrock, the drilling pressure of the fully hydraulic rotary reverse circulation drilling rig is dynamically adjusted according to the rock layer hardness: 25-35MPa for soft rock and 60-80MPa for hard rock; the rotation speed is adjusted in the range of 8-12rpm for soft rock and 5-8rpm for hard rock, and the slag is discharged by air lift reverse circulation.

7. The efficient pile construction method for large-diameter pile foundations in complex geological conditions according to claim 1, characterized in that: In step S4, the specific implementation of the air-lift reverse circulation + high-pressure jet composite hole cleaning process is as follows: the high-pressure jet device set at the bottom of the hole impacts and crushes the large-diameter sediment, and the air-lift reverse circulation system is simultaneously started to forcefully discharge the crushed sediment to the outside of the hole.

8. The efficient pile construction method for large-diameter pile foundations in complex geological conditions according to claim 1, characterized in that: In step S5, the mechanical connection joints of the steel cage are staggered by a distance of 35d (d is the diameter of the steel bar). The dual-machine coordinated hoisting adopts the lifting method of the main crane and the auxiliary crane. During the lowering of the steel cage, the guide frame ensures that it is centered with a deviation of 5cm.

9. The efficient pile construction method for large-diameter pile foundations in complex geological conditions according to claim 1, characterized in that: In step S6, the diameter of the conduit is 300mm, the concrete pouring speed is controlled at 2.5-3m / h, the over-pouring height after pouring is 0.8-1.0m, and the over-pouring part is subsequently removed by chiseling away the laitance to ensure the quality of the pile top.

10. The efficient pile construction method for large-diameter pile foundations in complex geological conditions according to claim 1, characterized in that: In step S7, the real-time monitoring equipment includes a borehole settlement monitor, a mud performance monitor, and a verticality monitor. The abnormal monitoring criteria are: borehole settlement of 5cm, mud sand content >8%, or verticality deviation >3cm. The corresponding emergency measures include adding casing, adjusting mud parameters, or stopping the machine for backfilling.

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