Land construction method for coastal backfill soft soil foundation ultra-long top section PHC pipe pile

Abstract

The invention provides a coastal backfill soft soil foundation ultra-long top section PHC pipe pile land construction method. The method comprises the following steps that S1, pile shoes of PHC pipe piles are welded; s2, selecting a lifting point of the PHC pipe pile; s3, site treatment is conducted, specifically, soft soil foundation pretreatment work is conducted in advance, soil in a soft soil body area and a spring soil area is excavated out, and high-quality soil is used for replacement; s4, a pile machine is in place; s5, constructing a bottom section PHC pipe pile; s6, the top section PHC pipe pile is hoisted; s7, alignment welding is conducted, specifically, limiting devices are welded in three directions of the top of the bottom section PHC pipe pile, and the butt joint precision is ensured; s8, pile sinking of a top section pile is conducted, specifically, the pile top of the PHC pipe pile is sunk to the designed elevation, and construction is completed; the construction method overcomes the limitation of existing land construction equipment, and has the advantages of being easy to operate, small in risk, capable of reducing the number of segments of the PHC pipe pile, improving the construction efficiency and reducing the construction cost on the premise that safety is guaranteed.

Description

[Technical field]

[0001] The invention relates to a waterway construction technology, in particular to a land construction method for an ultra-long top-section PHC pipe pile for backfilling a soft soil foundation along the coast. [Background technology]

[0002] PHC pipe piles, full name prestressed high-strength concrete pipe piles, are hollow cylindrical concrete prefabricated components made by prestressing and centrifugal forming processes, and cured by steam at 10 atmospheres (about 1.0 Mpa) and about 180°C. The standard section length is 10m, the diameter ranges from 300mm to 800mm, and the concrete strength grade is ≥C80. PHC pipe pile construction can adopt static pressure method and hammer method, which has the characteristics of fast speed, high efficiency and short construction period.

[0003] In actual wharf projects, PHC pipe piles are widely used due to their high strength, corrosion resistance and ease of construction. Compared with offshore PHC pipe pile construction, onshore PHC pipe pile construction has the characteristics of low equipment requirements, low cost and high safety, and is currently one of the mainstream methods for wharf pile foundation construction.

[0004] However, with the expansion of land reclamation in some coastal cities in my country, the geological areas in the coastal docks are weak. In order to ensure the bearing capacity of the pile foundation, the length of PHC piles has gradually increased. At present, the onshore PHC pile construction equipment has great limitations and cannot adapt to the changes in the length of PHC piles in time, so it is necessary to carry out segmented construction. The number of segments has a great impact on the efficiency of PHC pile sinking construction.

[0005] Therefore, the development of an onshore construction method for ultra-long top-section PHC pipe piles for coastal backfill of soft soil foundations is of great significance to the coastal terminal engineering construction industry. [Summary of the invention]

[0006] The present invention overcomes the limitations of existing land construction equipment and, under the premise of ensuring safety, provides a land construction method for super-long top-section PHC pipe piles in coastal backfill soft soil foundation with simple operation and low risk, thereby reducing the number of sections of the PHC pipe piles, improving construction efficiency and reducing construction costs.

[0007] In order to achieve the above-mentioned object of the invention, the technical solution adopted by the present invention is:

[0008] A land construction method for super-long top-section PHC pipe piles for backfilling soft soil foundation along the coast, comprising the following steps:

[0009] S1. Pile shoe welding of PHC pile

[0010] Carry out pile shoe welding in advance. When producing PHC piles, weld the pile shoe at the bottom of the bottom section pile. After the pile shoe welding is completed, the PHC piles can be shipped, thus reducing the construction process of PHC piles on site.

[0011] S2. Selection of hanging points for PHC piles

[0012] According to the arm parameters, wire rope arrangement and length of the top section PHC pile of the walking pile driver, the hoisting process was simulated using simulation software, and the forces on the PHC pile and the hoisting wire rope were calculated and analyzed through mathematical models.

[0013] S3. Site treatment

[0014] Carry out pretreatment of soft soil foundation in advance, remove the soil in soft and spring soil areas, and replace them with high-quality soil;

[0015] S4, pile driver in place

[0016] Move the walking pile driver and perform precise positioning to align the center of the diesel pile hammer cap with the designed center of the PHC pile;

[0017] During the construction of the pile driver, ensure that all four legs of the pile driver are on the ground to avoid excessive force on one leg, which may cause the leg to sink.

[0018] S5, bottom section PHC pile construction

[0019] S5.1. Connect the main hook of the walking pile driver to the steel wire rope pre-tied to the lifting point of the bottom PHC pile, connect the auxiliary hook of the walking pile driver to the bottom of the PHC pile, and limit the deviation of the pile position during the pile dragging process;

[0020] S5.2. The PHC pile is hoisted by coordinating the main hook and the auxiliary hook of the walking pile driver, and the top of the PHC pile is inserted into the hammer cap of the diesel pile hammer;

[0021] S5.3. Adjust the position of the PHC pile by adjusting the boom of the walking pile driver so that the pile coincides with the contour line of the designed pile position marked in advance;

[0022] S5.4. Lower the PHC pile and diesel pile hammer simultaneously, use the hammer's deadweight to press the PHC pile into the mud surface, and adjust the verticality of the PHC pile simultaneously;

[0023] S5.5, pile sinking construction, sink the top of the bottom section PHC pile to below the original ground;

[0024] S6, top section PHC pile hoisting

[0025] S6.1. After tying the hoisting wire rope to the pre-designed lifting point, connect it to the main hook of the walking pile driver, and simultaneously connect the auxiliary hook of the walking pile driver to the bottom of the pile;

[0026] S6.2. Raise the main hook and auxiliary hook simultaneously and start the hoisting operation;

[0027] S7, butt welding

[0028] S7.1. Weld limit devices in three directions on the top of the bottom section PHC pile to ensure docking accuracy;

[0029] S7.2. Adjust the boom of the walking pile driver and adjust the bottom position of the PHC pile through the limit wire rope at the bottom of the pile driver;

[0030] S7.3. After the docking is completed, the PHC piles are initially fixed by spot welding and the verticality is adjusted. After the final adjustment is completed, the wind shelter is set up and welding begins;

[0031] S8. Top pile sinking

[0032] Carry out pile sinking operation, sink the top of the PHC pipe pile to the designed elevation and complete the construction.

[0033] Furthermore, the process of selecting the lifting point of the PHC pile in step S2 also includes: moving the lifting point of the PHC pile to the pile tail as much as possible to reduce the length of the pile dragging while avoiding interference between the pile top and the boom and overloading of the wire rope during the lifting process.

[0034] Furthermore, the site treatment in step S3 also includes: in order to avoid the outriggers from sinking during the construction of the pile driver after rainy weather, steel plates are laid in the pile driver positioning area in advance to increase the contact area between the pile driver and the ground.

[0035] Furthermore, the site treatment in step S3 also includes: lowering the local mud surface elevation within 1m of the PHC pipe pile position area, increasing the driving depth of the first section pile and reducing the lifting pressure of the top section pile.

[0036] Furthermore, the hoisting of the top section PHC pipe pile in step S6 also includes: before the hoisting operation, adjusting the arm position of the walking pile driver to avoid collision between the top section pile and the bottom section pile that has been driven.

[0037] The beneficial effects of the present invention are:

[0038] The land construction method of the super-long top section PHC pipe pile overcomes the limitations of existing land construction equipment, and effectively relieves the lifting pressure of the top section PHC pipe pile by partially lowering the mud surface elevation and increasing the sinking depth of the bottom section PHC pipe pile. At the same time, the foundation pit formed by local excavation is used as a wind shield for welding operations, which can effectively block wind and rain from any direction, greatly ensuring the welding quality and laying the foundation for the overall quality of the project. Therefore, under the premise of ensuring safety, it has simple operation and low risk, effectively improving construction efficiency and reducing construction costs, including the following points:

[0039] (1) The number of PHC pile segments is reduced, the construction process is reduced, the construction efficiency is improved, and the integrity of the PHC pile is enhanced, so that the quality of pile sinking construction is guaranteed;

[0040] (2) According to the arm structure of the walking pile driver, the appropriate lifting point of the PHC pile can be selected to reduce the lifting risk and improve the lifting efficiency;

[0041] (3) For a walking pile driver with a fixed-length boom, the upper limit of the length of the top section of the PHC pipe pile that can be constructed by the walking pile driver can be increased, thereby reducing equipment limitations.

Brief Description of the Drawings

[0042] Figure 1 It is a schematic diagram of the hoisting process of the PHC pipe pile in the present invention. [Specific implementation method]

[0043] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0044] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0045] A land construction method for super-long top-section PHC pipe piles for backfilling soft soil foundation along the coast, comprising the following steps:

[0046] S1. Pile shoe welding of PHC pile

[0047] Carry out pile shoe welding in advance. When producing PHC piles, weld the pile shoe at the bottom of the bottom section pile. After the pile shoe welding is completed, the PHC piles can be shipped. This reduces the construction procedures of PHC piles on site, improves construction efficiency, and ensures construction progress.

[0048] S2. Selection of hanging points for PHC piles

[0049] According to the arm parameters, wire rope arrangement and the length of the top section of the PHC pile of the walking pile driver, the hoisting process is simulated using simulation software such as AUTOCAD software, and the forces on the PHC pile and the hoisting wire rope are calculated and analyzed through mathematical models;

[0050] In order to avoid interference between the pile top and the boom and overload of the wire rope during the lifting process, the PHC pile lifting point should be moved to the pile tail as much as possible to reduce the length of the pile dragging;

[0051] S3. Site treatment

[0052] Carry out pretreatment of soft soil foundation in advance, remove the soil in soft and spring soil areas, and replace them with high-quality soil;

[0053] In order to avoid the outriggers sinking during the construction of the pile driver after rainy weather, steel plates are placed in the pile driver positioning area in advance to increase the contact area between the pile driver and the ground. In addition, the local mud surface elevation is lowered within 1m of the PHC pipe pile position area to increase the driving depth of the first section of the pile and reduce the lifting pressure of the top section of the pile.

[0054] S4, pile driver in place

[0055] Move the walking pile driver and perform precise positioning to align the center of the diesel pile hammer cap with the designed center of the PHC pile;

[0056] During the construction of the pile driver, ensure that all four legs of the pile driver are on the ground to avoid excessive force on one leg, which may cause the leg to sink.

[0057] S5, bottom section PHC pile construction, such as Figure 1 As shown,

[0058] S5.1. Connect the main hook of the walking pile driver to the steel wire rope pre-tied to the lifting point of the bottom PHC pile, connect the auxiliary hook of the walking pile driver to the bottom of the PHC pile, and limit the deviation of the pile position during the pile dragging process;

[0059] S5.2. The PHC pile is hoisted by coordinating the main hook and the auxiliary hook of the walking pile driver, and the top of the PHC pile is inserted into the hammer cap of the diesel pile hammer;

[0060] S5.3. Adjust the position of the PHC pile by adjusting the boom of the walking pile driver so that the pile coincides with the contour line of the designed pile position marked in advance;

[0061] S5.4. Lower the PHC pile and diesel pile hammer simultaneously, use the hammer's deadweight to press the PHC pile into the mud surface, and adjust the verticality of the PHC pile simultaneously;

[0062] S5.5, pile sinking construction, sink the top of the bottom section PHC pile to below the original ground;

[0063] S6, top section PHC pile hoisting

[0064] S6.1. After tying the hoisting wire rope to the pre-designed lifting point, connect it to the main hook of the walking pile driver, and simultaneously connect the auxiliary hook of the walking pile driver to the bottom of the pile;

[0065] S6.2. Raise the main hook and auxiliary hook simultaneously and start the hoisting operation;

[0066] Moreover, before the lifting operation, the arm position of the walking pile driver should be adjusted to avoid the top pile from colliding with the bottom pile that has been driven;

[0067] S7, butt welding

[0068] S7.1. Weld limit devices in three directions on the top of the bottom section PHC pile to ensure docking accuracy;

[0069] S7.2. Adjust the boom of the walking pile driver and adjust the bottom position of the PHC pile through the limit wire rope at the bottom of the pile driver;

[0070] S7.3. After the docking is completed, the PHC piles are initially fixed by spot welding and the verticality is adjusted. After the final adjustment is completed, the wind shelter is set up and welding begins;

[0071] S8. Top pile sinking

[0072] Carry out pile sinking operation, sink the top of the PHC pipe pile to the designed elevation and complete the construction.

[0073] In this embodiment, since the number of PHC pipe pile sections is reduced, the construction process is correspondingly reduced, the construction efficiency is improved, and the integrity of the PHC pipe pile is enhanced, so that the quality of pile sinking construction is guaranteed; moreover, according to the boom structure of the walking pile driver, suitable lifting points of the PHC pipe pile can be selected to reduce the lifting risk and improve the lifting efficiency; at the same time, for the walking pile driver with a fixed-length boom, the upper limit of the top section length of the PHC pipe pile that can be constructed by the walking pile driver can be increased, thereby minimizing the limitations of the equipment.

[0074] The above-described embodiments are only preferred embodiments of the present invention and are not intended to limit the scope of implementation of the present invention. Except for the cases listed in the specific embodiments, all equivalent changes made according to the shape, structure and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A land construction method for super-long top section PHC pipe piles for backfilling soft soil foundation along the coast, characterized in that: The following steps are involved: S1. Pile shoe welding of PHC pile Carry out pile shoe welding in advance. When producing PHC piles, weld the pile shoe at the bottom of the bottom section pile. After the pile shoe welding is completed, the PHC piles can be shipped, thus reducing the construction process of PHC piles on site. S2. Selection of hanging points for PHC piles According to the arm parameters, wire rope arrangement and length of the top section PHC pile of the walking pile driver, the hoisting process was simulated using simulation software, and the forces on the PHC pile and the hoisting wire rope were calculated and analyzed through mathematical models. S3. Site treatment Carry out pretreatment of soft soil foundation in advance, remove the soil in soft and spring soil areas, and replace them with high-quality soil; S4, pile driver in place Move the walking pile driver and perform precise positioning to align the center of the diesel pile hammer cap with the designed center of the PHC pile; During the construction of the pile driver, ensure that all four legs of the pile driver are on the ground to avoid excessive force on one leg, which may cause the leg to sink. S5, bottom section PHC pile construction S5.

1. Connect the main hook of the walking pile driver to the steel wire rope pre-tied to the lifting point of the bottom PHC pile, connect the auxiliary hook of the walking pile driver to the bottom of the PHC pile, and limit the deviation of the pile position during the pile dragging process; S5.

2. The PHC pile is hoisted by coordinating the main hook and the auxiliary hook of the walking pile driver, and the top of the PHC pile is inserted into the hammer cap of the diesel pile hammer; S5.

3. Adjust the position of the PHC pile by adjusting the boom of the walking pile driver so that the pile coincides with the contour line of the designed pile position marked in advance; S5.

4. Lower the PHC pile and diesel pile hammer simultaneously, use the hammer's deadweight to press the PHC pile into the mud surface, and adjust the verticality of the PHC pile simultaneously; S5.5, pile sinking construction, sink the top of the bottom section PHC pile to below the original ground; S6, top section PHC pile hoisting S6.

1. After tying the hoisting wire rope to the pre-designed lifting point, connect it to the main hook of the walking pile driver, and simultaneously connect the auxiliary hook of the walking pile driver to the bottom of the pile; S6.

2. Raise the main hook and auxiliary hook simultaneously and start the hoisting operation; S7, butt welding S7.

1. Weld limit devices in three directions on the top of the bottom section PHC pile to ensure docking accuracy; S7.

2. Adjust the boom of the walking pile driver and adjust the bottom position of the PHC pile through the limit wire rope at the bottom of the pile driver; S7.

3. After the docking is completed, the preliminary fixation is carried out by spot welding, and the verticality of the PHC pile is adjusted. After the final adjustment is completed, the wind shelter is set up and welding begins; S8. Top pile sinking Carry out pile sinking operation, sink the top of the PHC pipe pile to the designed elevation, and complete the construction.

2. The method for land construction of super-long top section PHC pipe piles for backfilling soft soil foundation along the coast according to claim 1, characterized in that: The process of selecting the lifting point of the PHC pile in step S2 also includes: moving the lifting point of the PHC pile to the pile tail as much as possible to reduce the length of the pile dragging, while avoiding interference between the pile top and the boom and overloading of the wire rope during the lifting process.

3. The land construction method of an ultra-long top section PHC pipe pile for backfilling soft soil foundation along the coast according to claim 1 is characterized in that: The site treatment in step S3 also includes: in order to avoid the outriggers from sinking during the construction of the pile driver after rainy weather, steel plates are laid in the pile driver positioning area in advance to increase the contact area between the pile driver and the ground.

4. The method for constructing super-long top-section PHC pipe piles on land for backfilling soft soil foundation along the coast according to claim 1, characterized in that: The site treatment in step S3 also includes: lowering the local mud surface elevation within 1m of the PHC pipe pile position area, increasing the driving depth of the first section pile and reducing the lifting pressure of the top section pile.

5. The land construction method of super-long top section PHC pipe piles for backfilling soft soil foundation along the coast according to claim 1 is characterized in that: The hoisting of the top section PHC pipe pile in step S6 also includes: before the hoisting operation, adjusting the arm position of the walking pile driver to avoid collision between the top section pile and the bottom section pile that has been driven.

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