A construction method of a precast pipe pile integrating a lead hole and a pile sinking

Abstract

The application relates to the technical field of foundation treatment equipment, in particular to a hole leading and pile sinking integrated prefabricated pipe pile construction method, which is used for pile sinking construction of the prefabricated pipe pile; a movable and rotatable pile tip is arranged in the prefabricated pipe pile; the pile tip and the prefabricated pipe pile are of a split structure; the pile tip is driven to move and rotate to agitate the soil layer at the pile end of the prefabricated pipe pile in the pile sinking process, so that the soil layer in the pile sinking range of the prefabricated pipe pile is locally softened; after the soil layer is locally softened, the pile sinking construction of the prefabricated pipe pile is continuously carried out until the design depth. The application has the advantages that the application is suitable for the prefabricated pipe pile sinking process engineering construction; when locally large-area hard soil layers are encountered in the pile sinking process, the hard soil layers can be quickly loosened and treated, the sinking resistance of the hard soil layers to the prefabricated pipe pile is quickly reduced, and the pipe sinking efficiency is greatly improved.

Description

Technical Field

[0001] This invention relates to the field of foundation treatment equipment technology, and in particular to a construction method for precast pipe piles that integrate drilling and pile driving. Background Technology

[0002] Precast concrete piles are widely used in most building construction projects due to their strong technical advantages. They can be optimized and adjusted during construction, effectively shortening the construction cycle while ensuring project quality. Their characteristics are as follows: low production cost, low reinforcement ratio, saving steel, hollow piles are very environmentally friendly, small diameter, large specific surface area, high bearing capacity per cubic meter of concrete, simple construction, low technical difficulty, short construction period, and continuous construction. In loose soil and unsaturated fill, they are positive, playing a role in densification and improving bearing capacity.

[0003] However, when encountering hard soil layers during the driving of precast pipe piles, the driving force is insufficient to overcome the soil layer resistance due to the large resistance at the pile end, which often leads to driving difficulties or even failure, causing inconvenience to the construction. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of the prior art by providing a precast pipe pile construction method that integrates pre-drilling and pile driving. By using a pile tip that can be positioned inside the precast pipe pile, the precast pipe pile can stir the hard soil layer during the pile driving process, which facilitates the implementation of pile driving construction.

[0005] The objective of this invention is achieved through the following technical solutions:

[0006] A construction method for precast pipe piles integrating pre-drilling and pile driving, wherein the precast pipe piles are driven into the soil layer through pile driving construction, characterized in that the construction method includes the following steps:

[0007] The precast pipe piles are driven into the ground.

[0008] A movable and rotatable pile tip is set inside the precast pipe pile. The pile tip and the precast pipe pile are separate structures. Driving the pile tip to move and rotate will agitate the soil layer at the pile tip during the pile driving process, making the soil layer within the pile driving range of the precast pipe pile locally soft.

[0009] Once the soil layer becomes locally soft, continue the driving of the precast pipe piles until they reach their designed depth.

[0010] The pile tip is connected to a rotary cylinder, which has a retractable and simultaneously rotating piston rod, one end of which is detachably connected to the pile tip.

[0011] After the precast pipe pile driving construction is completed, the rotating hydraulic cylinder is retrieved, and the pile tip is buried at the bottom of the precast pipe pile.

[0012] The pile tip is connected to a positioning cylinder assembly, which has a retractable support plate. When the pile tip agitates the soil layer at the pile end, the positioning cylinder assembly unfolds the support plate and supports the inner surface of the precast pipe pile, so that the pile tip agitates the soil layer of the pile segment while in a positioned state.

[0013] After the precast pipe pile driving construction is completed, the positioning cylinder assembly is retrieved, and the pile tip is buried at the bottom of the precast pipe pile.

[0014] The pile driving construction is one of the following: hammer driving, vibratory driving, and static pressure driving.

[0015] The advantages of this invention are: it is applicable to the construction of precast pipe pile driving process; when encountering local or large areas of hard soil during the driving process, it can quickly loosen the hard soil layer, rapidly reduce the driving resistance of the hard soil layer to the precast pipe pile, and significantly improve the driving efficiency; the structure is simple and reliable, can significantly improve construction efficiency, achieve protection of the pile pipe, effectively avoid the influence of soil layer on the device during operation, is easy to maintain, and is suitable for promotion. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the construction state of the present invention;

[0017] Figure 2 This is a schematic diagram of the structure of the present invention;

[0018] Figure 3 This is a schematic diagram of the structure of the hydraulic cylinder assembly in this invention;

[0019] Figure 4 This is a schematic diagram of the support plate in this invention;

[0020] Figure 5 This is a schematic diagram of the pile tip structure in this invention. Implementation

[0021] The features and other related features of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments, so as to facilitate understanding by those skilled in the art:

[0022] like Figure 1-5 As shown in the figure, each of the markings represents: positioning cylinder assembly 1, rotating cylinder 2, support plate 3, connecting sleeve 4, pile tip 5, precast pipe pile 6, pile driving equipment 7, lifting point 11, connecting interface 12, piston rod 13, connecting stiffener 31, groove 51, boss stop 52, pile tip plate 53, and stiffener 54.

[0023] Example: Figure 1 As shown, in this embodiment, the precast pipe pile construction method integrating drilling and pile driving is used for precast pipe pile 6. The precast pipe pile 6 is driven by pile driving equipment 7, which can effectively solve the problem of difficulty or inability to drive piles when encountering local hard soil layers or excessive pile end resistance during the pile driving process.

[0024] The construction method in this embodiment can be combined with, for example: Figures 2 to 5 The device shown enables pile driving, but is not limited to... Figures 2 to 5 The device shown can be replaced by other devices that can achieve the same function.

[0025] Combination Figures 2 to 5 The device shown in this embodiment, the construction method of precast pipe pile integrating pilot hole and pile driving includes the following steps:

[0026] This embodiment includes the following construction methods during construction:

[0027] 1) Construction preparation;

[0028] 2) On-site surveying and layout;

[0029] 3) Pile driving equipment 7 is in place;

[0030] 4) Device assembly and positioning;

[0031] 5) Pile driving construction;

[0032] During the pile driving process, there are two main scenarios:

[0033] a) If the soil at the pile tip is loose and the pile driving is smooth, then construction can proceed normally;

[0034] b) When the pile tip of the precast pipe pile 6 encounters a hard soil layer during the pile driving process, and the pile tip resistance is too great, making pile driving difficult or impossible, then the following measures are taken: Figures 2 to 5 The device shown agitates the hard soil layer, thereby facilitating the driving of the precast pipe piles 6.

[0035] Specifically, it consists of a positioning cylinder assembly 1, a rotating cylinder 2, a support plate 3, a connecting sleeve 4, and a pile tip 5.

[0036] The positioning cylinder assembly 1 has a lifting point 11 on its upper part, which can be connected to lifting machinery via a wire rope to achieve the lifting and placement of the entire device. The positioning cylinder assembly 1 has two symmetrical piston rods 13, each end of which is connected to a support plate 3. A connection interface 12 for connecting to the rotating cylinder 2 is provided at the lower part of the positioning cylinder assembly 1.

[0037] The inner sides of the two support plates 3 are provided with connecting stiffeners 31, which can connect the end of the piston rod 13 and ensure the structural strength of the support plates 3. The outer arc surface of the support plate 3 is the same as the inner diameter of the precast pipe pile 6. In use, the support plate 3 can extend outward or retract inward under the drive of the piston rod 13 of the positioning cylinder assembly 1. When the support plate 3 is pushed outward under the drive of the piston rod 13, it can fit tightly against the inner surface of the precast pipe pile 6, thereby realizing the positioning of the whole device and ensuring verticality.

[0038] The rotary cylinder 2 is a high-torque hydraulic cylinder with a retractable and simultaneously rotating piston rod. Its top end is connected to the positioning cylinder assembly 1 through the connection interface 12, and its bottom end is connected to the connecting sleeve 4. The connecting sleeve 4 is used to realize the connection between the rotary cylinder 2 and the pile tip 5, so that the rotary cylinder 2 can drive the pile tip 5 through the connecting sleeve 4.

[0039] The lower end of the connecting sleeve 4 has a straight, cross-shaped, or star-shaped flange. Simultaneously, a groove 51 matching the flange of the connecting sleeve 4 is provided on the upper surface of the pile tip 5, allowing the pile tip 5 to be connected to the flange on the connecting sleeve 4 in a limiting engagement. This enables the pile tip 5 to extend, retract, and rotate simultaneously under the drive of the rotating cylinder 2, thereby agitating the hard soil layer at the pile tip within the designed pile driving depth range of the precast pipe pile 6. This softens the soil layer locally within the pile driving range of the precast pipe pile 6, facilitating pile driving construction. Furthermore, the limiting engagement between the connecting sleeve 4 and the pile tip 5 facilitates the retrieval of the device.

[0040] In this embodiment, the connection between the connecting sleeve 4 and the pile tip 5 is mainly used to transmit the propulsive force and rotational driving force between the rotating cylinder 2 and the pile tip 5. That is, the connecting sleeve 4 can drive the pile tip 5 to rotate and further advance it towards the hard soil layer through this connection. In some cases, the connecting sleeve 4 and the pile tip 5 can also adopt other connection structures, so that the pile tip 5 can reciprocate along the depth direction under the drive of the rotating cylinder 2.

[0041] The pile tip 5 is composed of a boss stop 52, a pile tip plate 53, and a reinforcing plate 54. The boss stop 52 is matched with the inner diameter of the precast pipe pile 6, and a groove 51 is formed on the boss stop 52. The boss stop 52 is located above the pile tip plate 53, and a reinforcing plate 54 is provided below the pile tip plate 53 to form a cone shape, so as to facilitate pile driving and agitation of hard soil layers.

[0042] In use, hydraulic oil is supplied to the positioning cylinder assembly 1, pushing its piston rod 13 to extend outward, thereby moving the support plate 3 outward until the outer arc surface of the support plate 3 contacts and fits against the inner circular surface of the precast pipe pile 6, thus positioning the device and keeping it fixed under the pressure of the cylinder. Afterward, the piston rod of the rotating cylinder 2 extends and rotates, contacting the groove 51 on the pile tip 5 through the flange of the connecting sleeve 4 installed at the end of the piston rod. This downward pressure on the pile tip 5 simultaneously causes it to rotate, thus agitating the hard soil layer at the pile tip and softening it locally. Once the pile tip resistance is reduced, pile driving can proceed. When the hard soil layer is thick, repeated agitation can be used to assist the pipe pile's sinking until the designed depth is reached.

[0043] During this process, the agitation of the soil layer at the pile tip 5 is controlled, mainly referring to the controllable agitation depth. When the pile tip 5 is positioned by the positioning cylinder assembly 1, its position within the precast pipe pile 6 is known. At the same time, the extension and retraction of the pile tip 5 are also controlled by the rotating cylinder 2. Therefore, the overall agitation depth range of the pile tip 5 is controllable, achieving controllable agitation of the hard soil layer at the pile tip, thereby avoiding agitation of the soil layer below the designed depth range of the precast pipe pile 6, which would lead to a loss of pile tip bearing capacity.

[0044] 6) After pile driving is completed, the piston rod 13 of the positioning cylinder assembly 1 drives the support plate 3 to retract, making the diameter of the device smaller than the inner diameter of the precast pipe pile 6, and the device is then retrieved. The pile tip 5 is embedded at the bottom of the pile end of the precast pipe pile 6, thereby further improving the pile end bearing capacity of the precast pipe pile 6. Afterwards, the pile driving equipment 7 is moved to the next pile driving position for pile driving operation.

[0045] 7) The site is level.

[0046] In this embodiment, the positioning cylinder assembly 1 is a combination of a double-rod hydraulic cylinder or two single-rod hydraulic cylinders, so that the positioning cylinder assembly 1 has piston rod ends that match the number of support plates 3. This allows each support plate 3 to be connected to a piston rod that can be independently controlled for extension and retraction. Therefore, when the number of support plates 3 changes, for example, when four evenly arranged support plates 3 are used, a corresponding number of hydraulic cylinders can be configured, such as two double-rod hydraulic cylinders or four single-rod hydraulic cylinders.

[0047] The device in this embodiment is applicable to various pile driving methods such as hammer pile driving, vibratory pile driving, and static pressure pile driving, which greatly improves pile driving efficiency.

[0048] Although the above embodiments have described the concept and embodiments of the present invention in detail with reference to the accompanying drawings, those skilled in the art will recognize that various improvements and modifications can still be made to the present invention without departing from the scope of the claims, and therefore will not be elaborated here.

Claims

1. A construction method for precast pipe piles integrating pre-drilling and pile driving, wherein the precast pipe piles are driven into the soil layer through pile driving construction, characterized in that: The construction method includes the following steps: The precast pipe piles are driven into the ground. A movable and rotatable pile tip is set inside the precast pipe pile. The pile tip and the precast pipe pile are separate structures. Driving the pile tip to move and rotate will agitate the soil layer at the pile tip during the pile driving process, making the soil layer within the pile driving range of the precast pipe pile locally soft. When the soil layer becomes locally soft, continue the pile driving construction of the precast pipe piles until the designed depth is reached. The pile tip is connected to a rotary cylinder, which has a retractable and simultaneously rotating piston rod, and one end of the piston rod is detachably connected to the pile tip. The pile tip is connected to a positioning cylinder assembly, which has a retractable support plate. When the pile tip agitates the soil layer at the pile tip, the positioning cylinder assembly unfolds the support plate and supports the inner surface of the precast pipe pile, so that the pile tip agitates the soil layer at the pile tip while it is in a positioned state. After the precast pipe pile driving construction is completed, the positioning cylinder assembly is retrieved, and the pile tip is buried at the bottom of the precast pipe pile.

2. The construction method for precast pipe piles integrating pre-drilling and pile driving according to claim 1, characterized in that: After the precast pipe pile driving construction is completed, the rotating hydraulic cylinder is retrieved, and the pile tip is buried at the bottom of the precast pipe pile.

3. The construction method for precast pipe piles integrating pre-drilling and pile driving according to claim 1, characterized in that: The pile driving construction is one of the following: hammer driving, vibratory driving, and static pressure driving.

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