Ultra-deep large-diameter tubular pile hoisting process

Abstract

The invention discloses an ultra-deep large-diameter tubular pile hoisting process which comprises the following process steps: 1) determining an estimated pile length and a maximum hoisting capacity according to a tubular pile material and geological conditions, and selecting a 150t crawler crane; (2) butt joint with a tubular pile manufacturer is conducted, a reserved sleeve with the diameter being 60 mm and two rows of hoisting holes with the interval being 50 mm are formed in the hoisting side of the tubular pile, and the design of reinforcing ribs is deepened; (3) a steel bar with the diameter being phi 55 mm is inserted into a hoisting hole in the upper portion of the pile end, a common steel wire safety pin with the diameter being 3 mm is arranged, two steel wire ropes with the diameter being 39 mm are used for surrounding the outer wall of the pipe pile for hoisting, and the safety coefficient of the steel wire ropes is 6; (4) clamping the pipe pile by a special clamp after the pile hole is in place, inserting a steel bar into a hoisting hole in the lower part of the pile end, and loosening the steel wire rope after confirming the fixation, and (5) lowering the pile at the speed of 1m / min after the end plate is welded and cooled for 8min, and repeating the operation until the whole pile is completed through multiple anti-slip designs, so that the hoisting safety and quality of the ultra-deep large-diameter pipe pile are guaranteed.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of pipe pile hoisting, in particular to a super-deep large-diameter pipe pile hoisting process. BACKGROUND

[0002] The existing conventional prefabricated pipe pile hoisting process is mostly used for shallow foundation engineering, and the hoisting equipment used cannot meet the hoisting weight requirements of super-deep large-diameter pipe piles, and cannot adapt to the pipe pile hoisting load under super-deep working conditions.

[0003] The conventional process only uses ordinary steel wire ropes to embrace the outer wall of the pipe pile for hoisting, and after the self-weight of the super-deep large-diameter pipe pile is greatly increased, this method cannot prevent the steel wire rope from slipping off the outer wall of the pipe pile during hoisting, and there is a safety risk of the pipe pile falling. SUMMARY

[0004] In view of the above technical problems, the present application solves the problems of insufficient hoisting weight of conventional hoisting equipment and lack of effective anti-slip measures in conventional hoisting in the prior art.

[0005] In order to achieve the above-mentioned purpose, the technical solution adopted by the present application is as follows: a super-deep large-diameter pipe pile hoisting process, comprising the following steps:

[0006] S1: selection of hoisting equipment: according to the pipe pile material specified in the construction drawing and the geological conditions explored in the geological exploration data, the estimated pile length and maximum lifting weight of the pipe pile after pile formation are determined, and a 150t crawler crane is selected as the hoisting equipment;

[0007] S2: deepening design of prefabricated pipe pile hoisting hole: interfacing with the prefabricated pipe pile production manufacturer, setting a reserved sleeve on the hoisting side during pipe pile production, and radially penetrating two rows of hoisting holes arranged along the axial direction, the hoisting holes and the pipe pile reinforcing ribs are pre-designed and manufactured by the pipe pile manufacturer according to the construction requirements;

[0008] S3: hoisting method: inserting a steel rod into the upper hoisting hole at the end of the pipe pile, and setting a safety pin on the steel rod to prevent it from falling off; two 39mm diameter steel wire ropes are used to embrace the outer wall of the pipe pile below the steel rod, and the pipe pile is gradually tightened by the force of the steel wire ropes during lifting, and the pipe pile is hoisted to the pile hole position;

[0009] S4: pile hole positioning and fixing: after the pipe pile is hoisted above the pile hole and lowered to the pile end position, the pipe pile is clamped using the existing mature clamp, and at the same time, the steel rod is inserted into the lower hoisting hole at the end of the pile, and after confirming that the steel rod and the existing mature clamp are fixed in place, the steel wire ropes in step S3 are loosened;

[0010] S5: welding and pile driving: welding the pipe pile end plate, loosening the existing mature clamp after 8min of welding cooling, and controlling the pipe pile to drive down at a speed of 1m / min;

[0011] Repeat step S3 for steel bar installation and steps S4-S5 until the welding of the entire pile formed by welding multiple sections of pipe piles is completed and the pile driving is completed; wherein, the pipe pile is an ultra-deep large-diameter precast pipe pile with specifications of PHC800AB130 or PHC1000AB130, and the length of a single section is 6m, 7m, 8m, 9m, 10m, 11m, 12m, 13m, 14m or 15m; the safety factor of the wire rope is 6.

[0012] To better realize the present invention, further, in step S1, the crane has a rated lifting capacity of 150t and a boom length of 40-76m, which meets the lifting height requirements of a single pipe pile with a maximum length of 15m, an exposed pile length of ≤2m at the borehole opening, a pile length above ground of no more than 17m, and a sling length of less than 20m; the boom length of the 150t crawler crane must be selected to meet the following requirement: the sum of the pile length above ground and the sling length is less than the boom length, to ensure that there is no height restriction problem during the pipe pile lifting process.

[0013] To better realize the present invention, further, in step S2, the detailed fabrication of the precast pipe pile hoisting hole needs to include the setting of reinforcing ribs. The reinforcing ribs are designed by the pipe pile manufacturer according to the weight of a single section of the pipe pile and the hoisting force requirements to ensure the structural strength of the pipe pile at the hoisting hole.

[0014] To better realize the present invention, further, in step S3, the steel bar is only used as an anti-slip safety measure and is not involved in the force calculation; the hoisting force is borne by the friction between the 39mm diameter steel wire rope and the outer wall of the pipe pile.

[0015] To better realize the present invention, further, in step S4, the clamping force of the existing mature clamp must meet the following requirements: under the action of the self-weight of the pipe pile, the pipe pile does not slide when fixed, and there is no structural damage at the contact point between the clamp and the outer wall of the pipe pile.

[0016] To better realize the present invention, in step S5, the cooling time of the end plate welding must be strictly controlled to 8 minutes, and the strength of the weld at the end plate of the pipe pile after cooling must meet the requirement that there is no risk of welding cracking during the pile driving process.

[0017] To better realize the present invention, in step S5, the pile driving speed is controlled at 1m / min to prevent the pile from impacting the bottom of the pile hole or the surrounding soil during the pile driving process, and to avoid pile displacement or pile body damage.

[0018] To better realize the present invention, further, in step S3, the breaking tensile force of the two 39mm diameter steel wire ropes needs to match the maximum lifting capacity and safety factor of the pipe pile to ensure that there is no risk of breakage when the steel wire rope is under stress, and the breaking tensile force is ≥456t.

[0019] To better realize the present invention, the process is further applicable to deep pile foundation engineering of precast pipe piles without soil displacement, which penetrates ultra-deep miscellaneous fill layers and reaches the design bearing layer through rotary drilling. It is not applicable to soil displacement pile construction in soft foundations or silty soil using conventional hammer driving or static pressure driving.

[0020] To better realize the present invention, in step S4, before loosening the wire rope, it is necessary to confirm by visual observation and tool inspection that: the lower steel bar has been fully inserted into the hoisting hole, the safety pin has been installed in place, and the existing mature clamps have been fully clamped to the outer wall of the pipe pile to prevent the pipe pile from falling into the pile hole.

[0021] The technical solution provided by this invention has the following advantages compared with the prior art:

[0022] 1. In this invention, a Φ55mm steel rod is inserted into the lifting hole at the upper end of the pipe pile. The steel rod is equipped with a 3mm ordinary steel wire safety pin, and two strands of 39mm diameter steel wire rope are used to encircle the outer wall of the pipe pile. This restricts the displacement of the steel wire rope on the outer wall of the pipe pile and blocks the slippage path of the steel wire rope. This prevents the pipe pile from falling due to the slippage of the steel wire rope during hoisting. It ensures the safety and controllability of the pipe pile hoisting process and reduces the risk of hoisting accidents.

[0023] 2. In this invention, during the positioning and fixing of the pile hole, a special clamp is first used to clamp the pipe pile, and then a Φ55mm steel rod is inserted into the lifting hole at the lower part of the pile end. This "clamp + lower steel rod" forms a double fixing structure, compensating for any slight loosening of the clamp. This prevents the pipe pile from falling into the pile hole due to slight loosening of the clamp. It ensures the stability of the pipe pile's position before pile formation, avoids damage to the pipe pile, and guarantees the quality of pile formation.

[0024] 3. In this invention, a 150t crawler crane (such as SCC1500A-2) is selected, with a boom length set at 40-76m. This covers the maximum lifting capacity (76t) and hoisting height requirements for ultra-deep, large-diameter pipe piles (pile length above ground ≤ 17m + sling length < 20m). This avoids hoisting failures due to overload or insufficient boom length. It also meets the requirements for matching the lifting weight and height of ultra-deep, large-diameter pipe piles, ensuring stable operation of the hoisting equipment.

[0025] 4. In this invention, the cooling time after welding the end plates is strictly controlled at 8 minutes, and the pile driving speed is controlled at 1 m / min. This ensures that the weld reaches the design strength after cooling and avoids impact of the pipe pile on the bottom of the pile hole and the surrounding soil during the pile driving process. It also prevents weld cracking and avoids pipe pile displacement and pile body damage. This ensures the structural strength of the pile joint, improves the stability of the pile driving process, and ensures the overall pile construction quality. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a process flow diagram of the present invention;

[0028] Figure 2 This is a schematic diagram of the overall structure of the present invention;

[0029] Figure 3 This is a schematic diagram showing the assembly of the precast pipe pile, steel bar, and safety pin in this invention.

[0030] Explanation of reference numerals in the attached drawings: 101—precast pipe pile; 102—lifting hole; 103—steel bar; 104—steel wire rope; 105—safety pin. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0032] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0033] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0034] In the description of this application, it should be noted that the use of terms such as "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer" to indicate orientation or positional relationships is based on the orientation or positional relationships shown in the accompanying drawings, or the orientation or positional relationships commonly used when the product is in use. These terms are used solely for the convenience of describing this application and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the use of terms such as "first" and "second" in the description of this application is only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0035] Furthermore, the use of terms such as "horizontal" and "vertical" in the description of this application does not imply that the component is required to be absolutely horizontal or suspended, but rather that it may be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," and does not mean that the structure must be completely horizontal, but rather that it may be slightly tilted.

[0036] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "set up," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0037] Example 1

[0038] like Figures 1 to 3 As shown, a process for hoisting ultra-deep, large-diameter pipe piles includes the following steps:

[0039] S1: Selection of hoisting equipment: Based on the pipe pile material specified in the construction drawings and the geological conditions explored in the geological survey data, determine the estimated pile length after the pipe pile is completed (e.g., the longest pile length is 94m) and the maximum lifting capacity (e.g., 76t for pipe pile), and select a 150t crawler crane (e.g., model SCC1500A-2) as the hoisting equipment.

[0040] S2: Detailed design of hoisting hole 102 for precast pipe pile 101: In coordination with the precast pipe pile 101 manufacturer, a pre-reserved sleeve (e.g., the pre-reserved sleeve diameter Φ60mm, matching the diameter of steel bar 103) is set on the hoisting side during pipe pile production, and two rows of hoisting holes 102 are radially through and spaced apart along the axial direction (e.g., the hole spacing between each row of hoisting holes 102 is 50mm). The hoisting holes 102 and the pipe pile reinforcing bars are pre-detailed and manufactured by the pipe pile manufacturer according to the construction requirements.

[0041] S3: Lifting method: Insert a steel rod 103 (e.g., diameter Φ55mm, length = pile diameter + 200mm) into the lifting hole 102 at the upper end of the pipe pile. A safety pin 105 (e.g., safety pin 105, 3mm ordinary steel wire) is installed on the steel rod 103 to prevent it from falling off. Two strands of 39mm diameter steel wire rope 104 (e.g., steel wire rope 104 material 6*37M+FC, grade 1770) are used to wrap around the outer wall of the pipe pile under the steel rod 103. During the lifting process, the steel wire rope 104 is stressed and gradually tightens the wrap around the pipe pile, and the pipe pile is lifted to the pile hole position.

[0042] S4: Pile hole positioning and fixing: After hoisting the pipe pile to the top of the pile hole and lowering it to the pile end position, use existing mature clamps to clamp the pipe pile (middle section of the pipe pile). At the same time, insert the steel rod 103 (for example, the steel rod 103 has a diameter of Φ55mm and a length of pile diameter (outer diameter) + 200mm) into the hoisting hole 102 at the lower part of the pile end. After confirming that the steel rod 103 is fixed in place with the existing mature clamps, loosen the wire rope 104 in step S3.

[0043] S5: Welding and lowering of the pile: Weld the end plate of the pipe pile. After the welding has cooled for 8 minutes (i.e., the cooling strength is met), release the existing mature clamps and lower the pipe pile at a speed of 1 m / min.

[0044] Repeat steps S3-S5 until the welding of the entire pile formed by welding multiple sections of pipe piles is completed and the pile driving is completed; wherein, the pipe pile is an ultra-deep large-diameter precast pipe pile 101, with specifications of PHC800AB130 or PHC1000AB130, and the length of a single section is 6m, 7m, 8m, 9m, 10m, 11m, 12m, 13m, 14m or 15m; the safety factor of the steel wire rope 104 is 6.

[0045] like Figures 1 to 3 As shown in this embodiment, in step S1, the crane has a rated lifting capacity of 150t and a boom length of 40-76m, which meets the lifting height requirements of a single pipe pile with a maximum length of 15m, an exposed pile length of ≤2m at the borehole opening, a pile length above ground of no more than 17m, and a sling length of less than 20m. The boom length of the 150t crawler crane must be selected to meet the following requirements: the sum of the pile length above ground (e.g., the pile length above ground of no more than 17m) and the sling length (e.g., the sling length of less than 20m) is less than the boom length, to ensure that there is no height restriction problem during the pipe pile hoisting process.

[0046] like Figures 1 to 3 As shown in this embodiment, in step S2, the detailed fabrication of the hoisting hole 102 of the precast pipe pile 101 needs to include the setting of reinforcing ribs. The reinforcing ribs are designed by the pipe pile manufacturer according to the weight of a single section of the pipe pile and the hoisting force requirements to ensure the structural strength of the pipe pile at the hoisting hole 102.

[0047] like Figures 1 to 3 As shown, in this embodiment, in step S3, the steel bar 103 is only used as an anti-slip safety measure and does not participate in the force calculation; the hoisting force is borne by the friction between the 39mm diameter steel wire rope 104 and the outer wall of the pipe pile.

[0048] like Figures 1 to 3 As shown in this embodiment, in step S4, the clamping force of the existing mature clamp must meet the following requirements: under the action of the self-weight of the pipe pile (for example, the maximum self-weight of the pipe pile corresponds to a lifting capacity of 76t), the pipe pile is fixed without slippage, and there is no structural damage at the contact point between the clamp and the outer wall of the pipe pile.

[0049] like Figures 1 to 3 As shown in this embodiment, in step S5, the cooling time of the end plate welding must be strictly controlled to 8 minutes, and the strength of the weld at the end plate of the pipe pile after cooling must meet the requirement that there is no risk of welding cracking during the pile driving process.

[0050] like Figures 1 to 3 As shown in this embodiment, in step S5, the pile driving speed is controlled at 1m / min to prevent the pile from impacting the bottom of the pile hole or the surrounding soil during the pile driving process, and to avoid pile displacement or pile body damage.

[0051] like Figures 1 to 3 As shown in this embodiment, in step S3, the breaking tensile force of the two 39mm diameter steel wire ropes 104 must match the maximum lifting capacity of the pipe pile (e.g., the maximum lifting capacity of the pipe pile is 76t) and the safety factor (e.g., the safety factor is 6) to ensure that the steel wire rope 104 has no risk of breaking when under stress, and the breaking tensile force is ≥456t.

[0052] like Figures 1 to 3 As shown in this embodiment, the process is applicable to the precast pipe pile 101 deep pile foundation project of non-displacement piles that penetrates ultra-deep miscellaneous fill layers and reaches the design bearing layer through rotary drilling. It is not applicable to the construction of displacement piles in soft foundations or silty soil using conventional hammer driving or static pressure driving.

[0053] like Figures 1 to 3 Figures 1 to 3 As shown in this embodiment, before loosening the wire rope 104 in step S4, it is necessary to confirm by visual observation and tool inspection that: the lower steel bar 103 has been fully inserted into the hoisting hole 102, the safety pin 105 has been installed in place, and the existing mature clamps have been fully clamped to the outer wall of the pipe pile to prevent the pipe pile from falling into the pile hole.

[0054] Specifically,

[0055] 1. Selection of hoisting equipment

[0056] First, based on the specifications of the pipe pile material specified in the construction drawings (e.g., PHC800AB130 / PHC1000AB130) and the geological conditions explored in the geological survey data, determine the key parameters after the pipe pile is completed:

[0057] Estimated pile length: Maximum 94m (segmented hoisting and splicing).

[0058] Maximum lifting capacity: 76t (lifting load corresponding to the maximum self-weight of a single pipe pile).

[0059] Based on the above calculation parameters, the SCC1500A-2 crawler crane is selected as the lifting equipment, and its core parameters must meet the following requirements:

[0060] Rated lifting capacity: 150t (covering a maximum lifting capacity of 76t, with a safety margin).

[0061] Crane boom length: 40-76m (matching hoisting height requirements: single section of pipe pile maximum 15m + exposed pile length at borehole ≤ 2m = pile length above ground ≤ 17m, stacked sling length < 20m, total height < 37m, crane boom length must be greater than this total height to avoid hoisting height limitation).

[0062] Operational stability: It must meet the anti-overturning requirements during the hoisting of ultra-deep, large-diameter pipe piles to ensure that there is no risk of equipment displacement during the hoisting process.

[0063] Confirm the matching relationship between the crane's boom length, working radius, and lifting capacity: Under the working conditions of a maximum lifting capacity of 76t, a pile length of 17m above ground, and a sling length of 20m, the selected boom length (for example, boom length of 40-76m) can cover the actual lifting height, and the rated lifting capacity of 150t can meet the load requirements and avoid equipment overload.

[0064] 2. Detailed design of hoisting hole 102 for precast pipe pile 101

[0065] Establish a dedicated communication channel with the manufacturer of precast pipe pile 101 to clarify the design requirements for hoisting hole 102. This requires consideration of the pipe pile specifications (PHC800AB130 / PHC1000AB130) and single section length (6m / 7m / 8m / 9m / 10m / 11m / 12m / 13m / 14m / 15m) to ensure that the position of hoisting hole 102 matches the structural strength of the pipe pile.

[0066] The manufacturer is required to fabricate the following structures on the side where the pipe pile is hoisted:

[0067] Reserved sleeve: Φ60mm in diameter, which must match the diameter of the steel rod 103 to be used later (for example, the diameter of steel rod 103 is Φ55mm) to ensure that steel rod 103 can be inserted smoothly;

[0068] Lifting Hole 102: Two rows are set with a hole spacing of 50mm. The holes must be symmetrically distributed to ensure that the pipe pile is subjected to balanced force during lifting.

[0069] Reinforcing ribs: These are designed and manufactured by the manufacturer based on the weight of a single section of the pipe pile and the stress requirements during hoisting, to strengthen the structural strength of the pipe pile around hoisting hole 102 and prevent cracking of the pipe pile during hoisting.

[0070] Before the pipe piles leave the factory, the dimensions of the lifting hole 102 (e.g., hole diameter, spacing), the position of the reserved sleeve, and the welding quality of the reinforcing ribs must be checked to ensure that they meet the requirements of the lifting process and avoid the risk of subsequent lifting due to prefabrication defects.

[0071] 3. Lifting and hoisting preparation and operation

[0072] Prepare lifting rigging and safety components according to the following specifications, ensuring that the components meet the performance standards:

[0073] Wire Rope 104: Select 39mm diameter two-strand 104 wire rope, material is 6*37M+FC, grade 1770, the breaking tensile force must match the maximum lifting capacity of 76t and the safety factor of 6 (i.e., safety factor = breaking tensile force / actual force, to ensure no risk of breakage).

[0074] Steel bar 103: Diameter Φ55mm, length is "pipe pile diameter + 200mm", the material must have sufficient rigidity, it is only used as an anti-slip insurance measure and is not included in the stress calculation;

[0075] Safety pin 105: Made of 3mm ordinary steel wire, used to fix steel rod 103 and prevent steel rod 103 from falling out of lifting hole 102.

[0076] Insert the steel bar 103 into the lifting hole 102 at the top of the pipe pile end, ensuring that the steel bar 103 completely passes through the two rows of lifting holes 102 and that the exposed length at both ends is consistent.

[0077] Insert a 3mm ordinary steel wire safety pin 105 into the safety pin hole at the exposed end of the steel rod 103, and tighten both ends of the steel wire to prevent the steel rod 103 from slipping out of the hole during hoisting.

[0078] Two 39mm steel wire ropes 104 are wrapped around the outer wall of the pipe pile under the steel bar 103 to ensure that the steel wire ropes 104 are in close contact with the outer wall of the pipe pile. The lifting force is borne by the friction between the steel wire ropes 104 and the outer wall of the pipe pile.

[0079] Operate a 150t crawler crane to slowly lift wire rope 104. During the lifting process, the wire rope 104 will gradually tighten around the pipe pile under the force to prevent the pipe pile from shaking.

[0080] When the pipe pile is lifted to 30cm off the ground, the lifting is paused and the condition of the steel bar 103, safety pin 105 and wire rope 104 is checked: confirm that the steel bar 103 is not loose, the safety pin 105 is not detached and the wire rope 104 is not deviated. After confirming that there are no problems, the lifting continues and the pipe pile is lifted to the top of the pile hole.

[0081] 4. Pile hole positioning and fixing

[0082] Operate the crane to slowly lower the pipe pile, aligning it with the center of the pile hole. During the lowering process, the speed must be controlled to avoid collision between the pipe pile and the pile hole wall.

[0083] When the pile tip approaches the predetermined position at the bottom of the pile hole, slow down the lowering speed to ensure that the pile end plate makes stable contact with the bottom of the hole.

[0084] Using existing mature clamps (meeting the load-bearing capacity requirements, and the clamping force must ensure that the pipe pile does not slip under the maximum self-weight of 76t), the clamps are placed around the upper part of the pipe pile near the pile end, and the clamping mechanism is activated to make the clamps fit tightly against the outer wall of the pipe pile.

[0085] Check the clamping condition: Visually inspect the fit between the clamp and the pipe pile, and tap the clamp with a tool to confirm that there is no looseness, ensuring that the pipe pile is firmly fixed.

[0086] Insert a Φ55mm steel rod 103 into the lifting hole 102 at the bottom of the pile end, repeat the installation operation of the safety pin 105, and fix the steel rod 103 with 3mm ordinary steel wire.

[0087] After confirming that the lower steel bar 103 is fixed in place and that the existing mature clamps are tightened, slowly loosen the two 39mm steel wire ropes 104 at the top. During the loosening process, the condition of the pipe pile needs to be continuously observed to prevent the pipe pile from falling into the pile hole due to slight loosening of the clamps.

[0088] After the steel wire rope 104 is completely loosened, it is removed from the outer wall of the pipe pile, thus completing the positioning and fixing of the pipe pile.

[0089] 5. Welding and pile driving operations

[0090] If pile splicing is required (since the maximum pile length is 94m, multiple pipe pile sections need to be connected, and the existing pile splicing method can be used), hoist the next pipe pile section above the already positioned pipe pile according to the process of steps 3-4, so that the end plates of the two pipe pile sections are aligned and the gap is controlled within the allowable range of the specifications;

[0091] The end plate should be welded using existing mature welding methods. The welding method must comply with the pipe pile connection specifications to ensure that the weld is full and free of incomplete welds. During the welding process, it is necessary to prevent weld slag from falling into the pile hole.

[0092] After welding, wait 8 minutes for cooling to ensure that the strength of the end plate weld meets the standard (the tensile strength of the weld after cooling must meet the requirement that there is no risk of cracking during the pile driving process). It is strictly forbidden to carry out pile driving operation before the cooling is complete.

[0093] After cooling is complete, slowly release the existing clamps, and observe whether the pipe pile shifts during the release process;

[0094] Operate the crane or pile driving equipment to control the pile driving at a speed of 1m / min. This speed can prevent the pile from impacting the bottom of the pile hole or the surrounding soil, and avoid pile displacement or damage to the pile body.

[0095] After the pile is driven to the predetermined depth, if it is necessary to continue splicing the pile, repeat steps 3-5 until the entire pile is welded and driven to the design depth.

[0096] This process is only applicable to 101 deep pile foundation projects of non-displacement precast pipe piles that penetrate ultra-deep miscellaneous fill layers and reach the design bearing layer through rotary drilling. It is not applicable to displacement pile construction in soft foundations or silty soils using conventional hammer driving or static pressure driving, to avoid hoisting or pile driving quality problems caused by mismatched geological conditions.

[0097]

[0098]

[0099] The above description is merely a preferred embodiment of this application and is not intended to limit this application. For those skilled in the art, this application can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A hoisting process for ultra-deep, large-diameter pipe piles, characterized in that: Includes the following steps: S1: Selection of hoisting equipment: Based on the pipe pile material specified in the construction drawings and the geological conditions explored in the geological survey data, the estimated pile length and maximum lifting capacity after the pipe pile is completed are determined, and a 150t crawler crane is selected as the hoisting equipment. S2: Detailed design of hoisting holes for precast pipe piles: In coordination with the precast pipe pile manufacturer, a pre-reserved sleeve is set on the hoisting side during the production of the pipe pile, and two rows of hoisting holes are radially opened and spaced apart along the axial direction. The hoisting holes and pipe pile reinforcing bars are pre-detailed and manufactured by the pipe pile manufacturer according to the construction requirements. S3: Lifting method: Insert a steel bar into the lifting hole at the top of the pipe pile end, and set a safety pin on the steel bar to prevent it from falling off; use two 39mm diameter steel wire ropes to wrap around the outer wall of the pipe pile under the steel bar. During the lifting process, the steel wire ropes will gradually tighten the wrap around the pipe pile under the force, and lift the pipe pile to the pile hole position. S4: Pile hole positioning and fixing: After hoisting the pipe pile to the top of the pile hole and lowering it to the pile end position, use existing mature clamps to clamp the pipe pile. At the same time, insert the steel rod into the hoisting hole at the bottom of the pile end. After confirming that the steel rod is fixed in place with the existing mature clamps, loosen the wire rope in step S3. S5: Welding and lowering of the pile: Weld the end plate of the pipe pile. After the welding has cooled for 8 minutes, release the existing clamps and lower the pipe pile at a speed of 1 m / min. Repeat step S3 for steel bar installation and steps S4-S5 until the welding of the entire pile formed by welding multiple sections of pipe piles is completed and the pile driving is completed; wherein, the pipe pile is an ultra-deep large-diameter precast pipe pile with specifications of PHC800AB130 or PHC1000AB130, and the length of a single section is 6m, 7m, 8m, 9m, 10m, 11m, 12m, 13m, 14m or 15m; the safety factor of the wire rope is 6.

2. The ultra-deep large-diameter pipe pile hoisting process according to claim 1, characterized in that: In step S1, The crane has a rated lifting capacity of 150t and a boom length of 40-76m, which meets the lifting height requirements of a single pipe pile with a maximum length of 15m, an exposed pile length of ≤2m at the borehole opening, a pile length above ground of no more than 17m, and a sling length of less than 20m. The selection of the boom length of the 150t crawler crane must meet the following requirement: the sum of the pile length above ground and the sling length must be less than the boom length to ensure that there are no height restrictions during the pipe pile hoisting process.

3. The ultra-deep large-diameter pipe pile hoisting process according to claim 1, characterized in that: In step S2, The detailed fabrication of the precast pipe pile hoisting hole must include the installation of reinforcing ribs. These reinforcing ribs are designed by the pipe pile manufacturer based on the weight of a single pipe pile section and the hoisting stress requirements to ensure the structural strength of the pipe pile at the hoisting hole.

4. The ultra-deep large-diameter pipe pile hoisting process according to claim 1, characterized in that: In step S3, The steel bar is only used as an anti-slip safety measure and is not included in the stress calculation; the hoisting stress is borne by the friction between the 39mm diameter steel wire rope and the outer wall of the pipe pile.

5. The ultra-deep large-diameter pipe pile hoisting process according to claim 1, characterized in that: In step S4, The clamping force of the existing mature clamps must meet the following requirements: under the action of the pipe pile's own weight, the pipe pile should not slip when fixed, and there should be no structural damage at the contact point between the clamp and the outer wall of the pipe pile.

6. The ultra-deep large-diameter pipe pile hoisting process according to claim 1, characterized in that: In step S5, The cooling time for the end plate welding must be strictly controlled to 8 minutes. After cooling, the strength of the welded joint of the pipe pile end plate must meet the requirement that there is no risk of welding cracking during the pile driving process.

7. The ultra-deep large-diameter pipe pile hoisting process according to claim 1, characterized in that: In step S5, The pile driving speed is controlled at 1m / min to prevent impact on the bottom or surrounding soil of the pile hole during the pile driving process, and to avoid pile displacement or damage to the pile body.

8. The ultra-deep large-diameter pipe pile hoisting process according to claim 1, characterized in that: In step S3, The breaking strength of the two 39mm diameter steel wire ropes must match the maximum lifting capacity and safety factor of the pipe pile to ensure that there is no risk of breakage when the steel wire ropes are under stress, and the breaking strength is ≥456t.

9. The ultra-deep large-diameter pipe pile hoisting process according to claim 1, characterized in that: The process is applicable to deep pile foundation engineering of precast pipe piles without soil displacement, which penetrates ultra-deep miscellaneous fill layers and reaches the design bearing layer through rotary drilling. It is not applicable to soil displacement pile construction in soft foundations or silty soils using conventional hammer driving or static pressure driving.

10. The ultra-deep large-diameter pipe pile hoisting process according to claim 1, characterized in that: In step S4, Before loosening the wire rope, it is necessary to visually inspect and check with tools to confirm that: the lower steel bar has been fully inserted into the hoisting hole, the safety pin has been installed in place, and the existing mature clamps have been fully clamped to the outer wall of the pipe pile to prevent the pipe pile from falling into the pile hole.

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