Static pressure pile sinking construction method for high-strength concrete pipe pile under complex soil foundation condition

Abstract

The invention discloses a static pressure pile sinking construction method for a high-strength concrete pipe pile under a complex soil foundation condition, and relates to the technical field of static pressure pile construction. Measuring a pile position; pile position numbering: numbering the measured and positioned pile foundations, carrying out regional division, and numbering each region according to parity; a pile machine is in place; a steel wire rope and a rigging for hoisting are tied firstly, and then the upper portion of the pile is bound through the rigging; hoisting the precast pile to a pile machine clamp, and enabling the clamp to tightly hold the pile body; then the position of the pile foundation is adjusted, and the prefabricated pile tip is vertically aligned with the pile position center and slowly inserted into soil; after the prefabricated pile tip is inserted into the pile position, the perpendicularity of the pile is measured, and the vertical deviation of the prefabricated pile does not exceed 0.5%; static pressure pile sinking; after the precast pile body is centered, a pile pressing oil cylinder is started, and the precast pile is slowly pressed down; when it is determined that the final pressure condition is met, the pressure should be stabilized immediately; and pile pressing is stopped after pressure stabilization. The technical problem that in the prior art, the state of a soil body is changed due to soil squeezing of a tubular pile is solved.

Description

Technical Field

[0001] The invention relates to the technical field of static pressure pile construction, in particular to a static pressure pile sinking construction method for high-strength concrete pipe piles under complex soil foundation conditions. Background Art

[0002] With the rapid development of urban construction in my country, prestressed high-strength concrete pipe piles have been used in many high-rise buildings in recent years, especially the static pressure method for pile pressure construction. Because it has many advantages, there is a lot of room for application and development.

[0003] Prestressed concrete pipe piles belong to soil-squeezing piles. When constructing soil-squeezing piles in complex soil foundation areas, due to the instantaneous incompressibility of the soil, the piles will displace a corresponding volume of soil when entering the soil. If the treatment measures are not appropriate, it will cause environmental problems in the surrounding area, and in serious cases, it will cause engineering accidents. There are many examples of engineering accidents caused by insufficient understanding of this. In recent years, with the application of pipe piles in high-rise buildings, especially in coastal areas with complex soil foundations and urban areas with dense buildings, the soil squeezing problem of pipe piles has become increasingly prominent, and the study of soil squeezing effect has become one of the hot topics in the geotechnical field. Summary of the invention

[0004] The purpose of the present invention is to make up for the deficiencies of the prior art, provide a static pressure pile sinking construction method for high-strength concrete pipe piles under complex soil foundation conditions, and solve the technical problem of soil state change caused by pipe pile squeezing in the prior art.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions: a static pressure pile sinking construction method of high-strength concrete pipe piles under complex soil foundation conditions, comprising the following steps:

[0006] Step 1: Measure the pile position: first lay out the axis of the building according to the construction drawing and coordinate control points, close it, and then measure and lay out the pile position according to the axis;

[0007] Step 2: Pile position numbering: The measured and located pile foundations are numbered and divided into regions, with each region numbered according to odd and even numbers;

[0008] Step 3: Pile driver in position: Drive the pile driver to the area position, aligning the center of the pile driver's clamping port with the center of the pile position;

[0009] Step 4: Pile lifting and pile insertion: first tie the wire rope and rigging for lifting, and then use the rigging to tie the upper part of the pile;

[0010] Lift the precast pile to the pile driver's clamp and make the clamp hold the pile tightly;

[0011] Then adjust the position of the pile foundation so that the prefabricated pile tip is vertically aligned with the center of the pile position and slowly insert it into the soil;

[0012] Step 5: Pile alignment: After the precast pile tip is inserted into the pile position, measure the verticality of the pile to ensure that the vertical deviation of the precast pile does not exceed 0.5%;

[0013] Step 6: Static pressure pile sinking: After the prefabricated pile body is centered, the pile pressure cylinder is started to slowly press the prefabricated pile down;

[0014] Step 7: Termination of pile driving: When it is determined that the final pressure conditions have been reached, pressure stabilization should be carried out immediately; after pressure stabilization, pile driving should be terminated.

[0015] In a further technical solution, before measuring the pile position in step 1, the site is prepared: the construction site is arranged, the site is leveled, debris is removed, and compacted, including removing surface attachments in the construction site and digging out tree roots, and the working area of ​​the site is rolled and leveled using mechanical equipment;

[0016] Lay ballast on the moving route of the pile driver to ensure the stable verticality and movement of the pile driver during the piling construction;

[0017] Temporary drainage ditches are set up on both sides of the roadbed to ensure smooth drainage and prevent the roadbed base from being soaked due to rainwater and affecting construction.

[0018] In a further technical solution, in step 2, after the pile foundations are numbered in different areas, the adjacent area pile foundations are constructed at intervals of seven days. The pile foundation construction in the odd-numbered areas is carried out first, and the pile foundation pressing construction in the even-numbered areas is carried out after most of the excess pore water pressure generated by the soil squeezing effect has dissipated.

[0019] In a further technical solution, in step 2, the construction area is divided and anti-crowding ditches are set: the construction area is divided according to the distribution of soil layers, and the first anti-crowding ditch is set around each construction area, and the second anti-crowding ditches are evenly set in the construction area. The first anti-crowding ditch and the second anti-crowding ditch are set to isolate the displacement of soil deep under the ground surface and block the stress transfer caused by soil squeezing.

[0020] In a further technical solution, in step 2, a sand well is set in the pile foundation construction area to accelerate the dissipation of pore water pressure caused by pile sinking, thereby reducing the impact of soil squeezing effect on the surrounding environment;

[0021] The sand well adopts a small diameter of 0.4m, with a spacing of 1.5-2.0m and a depth of 10m;

[0022] The sand wells are arranged in a plum blossom shape, with 2 or 3 rows set up around the pile sinking area, which has a significant effect on lowering the groundwater level and dissipating the pore water pressure.

[0023] In a further technical solution, in step 5, the pile foundations in the same area are constructed symmetrically from the middle to both sides, so that the construction directions of two adjacent rows of piles in the same area are opposite, avoiding squeezing to one side in a single direction resulting in different pressing depths and uneven foundation compaction, until the last pipe pile of the piling construction is completed.

[0024] Compared with the existing technology, the static pressure pile construction method of high-strength concrete pipe piles under complex soil foundation conditions has the following beneficial effects:

[0025] The present invention divides the pile foundation into regions with equal pile numbers, numbers each region, and performs pile pressing at intervals between the odd-numbered region and the even-numbered region. The pile foundation construction in the odd-numbered region is performed first, and the pile foundation pressing construction in the even-numbered region is performed after most of the excess pore water pressure generated by the soil squeezing effect has dissipated. The pile foundation in the same region is constructed symmetrically from the middle to both sides. At the same time, anti-squeezing trenches are set on the edges and inside of each construction region to block the stress transmission generated by soil squeezing, which can effectively release soil stress. Sand wells or plastic drainage boards are set in the pile foundation construction area to accelerate the dissipation of pore water pressure caused by pile sinking, thereby reducing the impact of soil squeezing effect on the surrounding environment. The present invention effectively weakens the soil squeezing effect of static piles in soft and hard alternating layered soil, effectively reduces pile position deviation, and effectively improves pile sinking efficiency and pile sinking quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0027] Figure 1 It is a schematic diagram of the construction of the pipe pile static pressure sinking of the present invention;

[0028] Figure 2 It is a flow chart of the implementation steps of the present invention. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] See also Figure 1-2 , the present invention provides a technical solution:

[0031] The steps of the static pressure pile construction method of high-strength concrete pipe piles under complex soil foundation conditions are as follows:

[0032] Step 1: Measure the pile position: first lay out the axis of the building according to the construction drawing and coordinate control points, close it, and then measure and lay out the pile position according to the axis;

[0033] Step 2: Pile position numbering: The measured and located pile foundations are numbered and divided into regions, with each region numbered according to odd and even numbers;

[0034] Step 3: Pile driver in place: Use the pile driver's slewing mechanism and the long and short boat travel mechanism to align the center of the pile driver's clamping port with the center of the pile position;

[0035] Step 4: Lifting and inserting piles: first tie up the wire rope and rigging for lifting, then use the rigging to tie up the upper part of the pile, lift the prefabricated pile to the pile driver clamp, and make the clamp hold the pile body tightly, then adjust the position of the pile foundation, align the pile tip vertically with the center of the pile position, and slowly insert it into the soil.

[0036] Step 5: Pile body centering: After the pile tip is inserted into the pile position, measure the verticality of the pile to ensure that the vertical deviation of the pile does not exceed 0.5%.

[0037] Step 6: Static pressure pile sinking; after the pile body is centered, start the pile driving cylinder to slowly press the pile down.

[0038] Step 7: Termination of pile driving: When it is determined that the final pressure conditions have been reached, pressure stabilization should be carried out immediately; after pressure stabilization, pile driving should be terminated.

[0039] The pile foundation is divided into regions with equal pile numbers, each region is numbered, and piles are pressed alternately between odd-numbered regions and even-numbered regions. Pile foundation construction is first carried out in odd-numbered regions, and pile foundation pressing construction is carried out in even-numbered regions after most of the excess pore water pressure generated by soil squeezing is dissipated. The pile foundation in the same region is constructed symmetrically from the middle to both sides. At the same time, anti-squeezing trenches are set on the edges and inside of each construction region to block the stress transmission caused by soil squeezing, which can effectively release soil stress, and sand wells or plastic drainage boards are set in the pile foundation construction area to accelerate the dissipation of pore water pressure caused by pile sinking, thereby reducing the impact of soil squeezing effect on the surrounding environment. The present invention effectively weakens the soil squeezing effect of static piles in soft and hard alternating layered soil, effectively reduces pile position deviation, and effectively improves pile sinking efficiency and pile sinking quality.

[0040] Further: (1) Site preparation: Arrange the construction site, level the site, remove debris, and compact it. Specifically, remove surface attachments and dig out tree roots in the construction site. Use mechanical equipment to roll and level the working area of ​​the site. If necessary, lay ballast on the moving route of the pile driver to ensure the stable verticality and movement of the pile driver during the pile driving construction. Set up temporary drainage ditches on both sides of the roadbed to ensure smooth drainage and avoid the roadbed base being soaked by rainwater, which affects the construction.

[0041] (2) After the pile foundation is numbered in different areas, the adjacent pile foundations are constructed seven days apart. The odd-numbered areas are constructed first, and the even-numbered areas are constructed after the excess pore water pressure generated by the soil squeezing effect has mostly dissipated. The change in the order of pile sinking will not reduce the total stress generated in the soil, but it can change the way the total stress acts. The disturbance of the surrounding soil by the first piles destroys the soil structure, and then the soil is reconsolidated. However, the properties of the soil are different from the original soil, and a certain resistance to displacement is generated. Therefore, the horizontal displacement of the soil caused by the pile foundation construction process is macroscopically consistent with the direction of pile sinking, and the first piles are squeezed more than the later piles. In view of this situation, the method of pile sinking in different areas can be adopted during construction, and the skipping method can be used to reduce the soil squeezing effect caused by pile sinking.

[0042] (3) Divide the construction area and set up anti-squeezing ditches: Divide the construction area according to the distribution of soil layers, and set up the first anti-squeezing ditch 1 around each construction area, and evenly set up the second anti-squeezing ditch 2 in the construction area. Setting up anti-squeezing ditches can block the displacement of soil deep below the ground surface and block the stress transmission caused by soil squeezing, which can effectively release soil stress and help drain water so that the excess pore water pressure does not increase.

[0043] (4) Sand wells 3 or plastic drainage boards are set up in the pile foundation construction area to accelerate the dissipation of pore water pressure caused by pile sinking, thereby reducing the impact of soil squeezing effect on the surrounding environment. Sand wells 3 have a small diameter of 0.4m, with a spacing of 1.5 to 2.0m and a depth of 10m. Sand wells 3 can be arranged in a plum blossom shape, with 2 or 3 rows set up around the pile sinking area, which has a significant effect on lowering the groundwater level and dissipating pore water pressure.

[0044] (5) In the same area, pile foundations are constructed symmetrically from the middle to both sides, so that the construction directions of two adjacent rows of piles are opposite, avoiding squeezing in a single direction to one side, resulting in different injection depths and uneven compaction of the foundation, until the last pipe pile of the piling construction is completed, effectively alleviating the stress release in the densely piled areas and reducing the impact of the soil squeezing effect.

[0045] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be considered exemplary and non-restrictive in all respects, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention.

Claims

1. A high-strength concrete pipe pile static pressure pile construction method under complex soil foundation conditions, characterized by: The steps include: Step 1: Measure the pile position: first lay out the axis of the building according to the construction drawing and coordinate control points, close it, and then measure and lay out the pile position according to the axis; Step 2: Pile position numbering: The measured and located pile foundations are numbered and divided into regions, with each region numbered according to odd and even numbers; Step 3: Pile driver in position: Drive the pile driver to the area position, aligning the center of the pile driver's clamping port with the center of the pile position; Step 4: Pile lifting and pile insertion: first tie the wire rope and rigging for lifting, and then use the rigging to tie the upper part of the pile; Lift the precast pile to the pile driver's clamp and make the clamp hold the pile tightly; Then adjust the position of the pile foundation so that the prefabricated pile tip is vertically aligned with the center of the pile position and slowly insert it into the soil; Step 5: Pile alignment: After the precast pile tip is inserted into the pile position, measure the verticality of the pile to ensure that the vertical deviation of the precast pile does not exceed 0.5%; Step 6: Static pressure pile sinking: After the prefabricated pile body is centered, the pile driving cylinder is started to slowly press the prefabricated pile down; Step 7: Termination of pile driving: When it is determined that the final pressure conditions have been reached, pressure stabilization should be carried out immediately; after pressure stabilization, pile driving should be terminated.

2. The method for static pressure pile sinking of high-strength concrete pipe piles under complex soil foundation conditions according to claim 1 is characterized in that: Before measuring the pile position in step 1, prepare the site: arrange the construction site, level the site, remove debris, and compact it, including removing surface attachments and digging out tree roots in the construction site. The working area of ​​the site is rolled and leveled with mechanical equipment; Lay ballast on the moving route of the pile driver to ensure the stable verticality and movement of the pile driver during the piling construction; Temporary drainage ditches are set up on both sides of the roadbed to ensure smooth drainage and prevent the roadbed base from being soaked due to rainwater and affecting construction.

3. The static pressure pile sinking construction method of high-strength concrete pipe piles under complex soil foundation conditions according to claim 1 is characterized by: In step 2, after the pile foundations are numbered in different areas, the adjacent area pile foundations are constructed seven days apart. The pile foundation construction in the odd-numbered areas is carried out first, and the pile foundation pressing construction in the even-numbered areas is carried out after most of the excess pore water pressure generated by the soil squeezing effect has dissipated.

4. The method for static pressure pile sinking of high-strength concrete pipe piles under complex soil foundation conditions according to claim 1 is characterized in that: In step 2, the construction area is divided and anti-crowding ditches are set up: the construction area is divided according to the distribution of soil layers, and the first anti-crowding ditch is set around each construction area, and the second anti-crowding ditch is evenly set up in the construction area. The first anti-crowding ditch and the second anti-crowding ditch are set up to isolate the soil displacement deep under the ground surface and block the stress transfer caused by soil squeezing.

5. The method for static pressure pile sinking of high-strength concrete pipe piles under complex soil foundation conditions according to claim 1 is characterized in that: In step 2, a sand well is set up in the pile foundation construction area to accelerate the dissipation of pore water pressure caused by pile sinking, thereby reducing the impact of soil squeezing effect on the surrounding environment; The sand well adopts a small diameter of 0.4m, with a spacing of 1.5-2.0m and a depth of 10m; The sand wells are arranged in a plum blossom shape, with 2 or 3 rows set up around the pile sinking area, which has a significant effect on lowering the groundwater level and dissipating the pore water pressure.

6. The method for static pressure pile sinking of high-strength concrete pipe piles under complex soil foundation conditions according to claim 1 is characterized in that: In step 5, the pile foundations in the same area are constructed symmetrically from the middle to both sides, so that the construction directions of two adjacent rows of piles in the same area are opposite, avoiding squeezing in a single direction to one side resulting in different pressing depths and uneven foundation compaction, until the last pipe pile of the piling construction is completed.

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