Precast concrete composite pipe pile for uplift and construction method
By setting slow-bonding prestressed steel strands in precast concrete composite pipe piles and tensioning them after the concrete has set, the problems of insufficient tensile bearing capacity and poor connection reliability of precast concrete pipe piles are solved, achieving efficient and reliable pull-out performance and low-cost construction method.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- HANJIA DESIGN GRP CO LTD
- Filing Date
- 2023-09-21
- Publication Date
- 2026-07-03
AI Technical Summary
Precast concrete pipe piles have relatively low tensile bearing capacity in pull-out engineering and poor reliability of pile body connection, which makes them prone to failure in engineering, limiting their application scope and increasing investment and extending the construction period.
Slow-bonded prestressed steel strands are installed inside concrete pipes. Tensioning is performed after the concrete has set, and a composite pipe pile is formed by combining the steel cage and the concrete core. The adhesive of the slow-bonded prestressed steel strands cures later than the concrete, thus achieving effective tensioning and anchoring of the steel strands.
It improves the tensile bearing capacity of precast concrete composite pipe piles, simplifies the tensioning operation, reduces steel consumption, reduces environmental impact, lowers project cost, and improves the reliability of pile connection and construction speed.
Smart Images
Figure CN117188438B_ABST
Abstract
Description
Technical Field
[0001] This disclosure relates to the field of tension pile technology, and in particular to precast concrete composite pipe piles that can be used for tension resistance and construction methods. Background Technology
[0002] With the development and utilization of underground space, the number and depth of basements are gradually increasing, and the required tensile strength of single piles is also increasing accordingly. Drilled cast-in-place piles are constructed by drilling holes and pouring concrete on-site using auger drilling rigs or submersible drilling rigs, which requires a large site area and sometimes discharges large amounts of mud, resulting in a significant environmental impact. Compared to drilled cast-in-place piles, precast concrete pipe piles have advantages such as faster construction speed, less environmental impact, higher degree of industrialization, and lower cost. However, due to their lower tensile strength and poor reliability of connections between multiple pipe pile sections and between the pile and the foundation, they are prone to failure and uplift accidents during engineering projects. This severely restricts the application of precast concrete pipe piles in uplift engineering. Some regions even stipulate that only the tensile strength of a single precast concrete pipe pile section can be considered, limiting the application scope of precast concrete pipe piles, leading to a significant increase in project investment and extended construction periods. Summary of the Invention
[0003] To address at least one of the aforementioned technical problems, this disclosure provides a precast concrete composite pipe pile for pull-out resistance and a construction method thereof, which features fast construction speed and minimal environmental impact. Furthermore, the finished pipe pile has high tensile bearing capacity, the tensioning operation of the loosely bonded prestressed steel strands is simple, the tensioning effect is good, and the amount of steel used is small, thus reducing costs.
[0004] According to one aspect of the inventive concept of this disclosure, a precast concrete composite pipe pile for pull-out resistance is provided, comprising:
[0005] At least two precast concrete pipes are configured to be pressed into the pre-set pile positions in the vertical direction in sequence;
[0006] A reinforcing cage is installed inside the precast concrete pipe;
[0007] The lower end of the loosely bonded prestressed steel strand is anchored at the bottom of the precast concrete pipe, and the upper end extends beyond the upper end of the precast concrete pipe.
[0008] A concrete core is disposed inside the precast concrete pipe, and the concrete core is cast and connected together with at least two sections of the precast concrete pipe.
[0009] The curing time of the slow-setting adhesive of the slow-bonding prestressed steel strand is later than the setting time of the concrete core. In response to the concrete core reaching a preset threshold strength, the slow-bonding prestressed steel strand is tensioned until the slow-setting adhesive cures.
[0010] According to some embodiments of this disclosure, the precast concrete composite pipe pile also includes:
[0011] Pipe pile joints are installed between two adjacent sections of the precast concrete pipe.
[0012] According to some embodiments of this disclosure, the wall thickness of at least two sections of the precast concrete pipe decreases sequentially from top to bottom.
[0013] According to some embodiments of this disclosure, the loosely bonded prestressed steel strand includes:
[0014] A long, slow-bonded prestressed steel strand is provided with a first anchoring end at the bottom of the precast concrete composite pipe pile and a first tensioning end at the top of the precast concrete composite pipe pile.
[0015] An auxiliary, slow-bonding prestressed steel strand is provided, with a second anchoring end located at the upper, middle, or lower part of the precast concrete composite pipe pile, and a second tensioning end located at the top of the precast concrete composite pipe pile.
[0016] According to some embodiments of this disclosure, the number of auxiliary loosely bonded prestressed steel strands is multiple, and the lengths of the multiple auxiliary loosely bonded prestressed steel strands are different.
[0017] According to some embodiments of this disclosure, the reinforcing cage includes:
[0018] Longitudinal reinforcement;
[0019] Circular stirrups are placed on the longitudinal reinforcement;
[0020] The slow-bonding prestressed steel strand is fixed to the reinforcing cage.
[0021] According to some embodiments of this disclosure, the precast concrete composite pipe pile also includes:
[0022] An anchor is provided at the lower end of the loosely bonded prestressed steel strand.
[0023] According to some embodiments of this disclosure, the number of continuous, gently bonded prestressed steel strands is at least two, and the continuous, gently bonded prestressed steel strands and the auxiliary gently bonded prestressed steel strands are evenly arranged along the circumference of the reinforcing cage.
[0024] According to some embodiments of this disclosure, the precast concrete composite pipe pile also includes:
[0025] A closed end cap is installed at the bottom of the precast concrete pipe at the lowest point. The closed end cap has a flat bottom or a conical bottom.
[0026] According to another aspect of the inventive concept of this disclosure, a construction method for a pull-out resistant precast concrete composite pipe pile is also provided, comprising:
[0027] At least two precast concrete pipe sections are driven into the target pile location;
[0028] The reinforcing cage is placed into the precast concrete pipe. The lower end of the continuous slow-bonding prestressed steel strand is anchored and fixed to the bottom of the reinforcing cage. The lower end of the auxiliary slow-bonding prestressed steel strand is anchored and fixed to the upper, middle or lower part of the reinforcing cage. The other end of the slow-bonding prestressed steel strand extends beyond the upper end of the precast concrete pipe.
[0029] The precast concrete pipe is then filled with concrete.
[0030] Continue pile driving until the piles are driven to the predetermined elevation;
[0031] Before the adhesive of the loosely bonded prestressed steel strand cures, the foundation pit is excavated, and the loosely bonded prestressed steel strand is tensioned and anchored.
[0032] The foundation construction is carried out, and the loosely bonded prestressed steel strands are tensioned and anchored within the foundation;
[0033] In this process, the adhesive is allowed to cure while maintaining a preset tension.
[0034] According to some embodiments of this disclosure, the loosely bonded prestressed steel strands remain vertical during the concrete core-filling operation.
[0035] According to some embodiments of this disclosure, the pile driving operation includes pressing, hammering, or implantation.
[0036] According to the embodiments of this disclosure, a precast concrete composite pipe pile for pull-out resistance and its construction method are provided. By setting a slow-bonded prestressed steel strand in the steel cage of the pipe pile, the slow-bonded prestressed steel strand is tensioned after the concrete core has solidified and reached the preset strength. In particular, the tensioning can be carried out after the foundation pit is excavated, and the adhesive is cured after the tensioning is completed, resulting in a bonded prestressed steel strand. The tensioning operation is simple, the tensioning effect is controllable, the prestress in the pile body is highly reliable, and the steel strand has good corrosion resistance. At the same time, it avoids the need for corrugated pipe laying and complex post-grouting process required for ordinary bonded prestressed steel strands. Therefore, it has both the construction simplicity of unbonded prestressed steel strands and the reliability of bonded prestressed steel strands. Attached Figure Description
[0037] Figure 1 This is a cross-sectional view of a precast concrete composite pipe pile according to an exemplary embodiment of the present disclosure;
[0038] Figure 2 yes Figure 1A cross-sectional view (AA) of the precast concrete composite pipe pile; and
[0039] Figure 3 This is a partial structural schematic diagram of the slow-bonding prestressed steel strand of a precast concrete composite pipe pile according to an exemplary embodiment of the present disclosure.
[0040] Figure 4 yes Figure 3 A partial structural schematic diagram of the slow-bonded prestressed steel strands of the precast concrete composite pipe pile shown from another perspective.
[0041] Figure 5 This is a schematic diagram of the connection structure between the top of a precast concrete composite pipe pile for uplift resistance and the foundation, according to exemplary embodiments of the present disclosure; and
[0042] Figure 6 This is a flowchart of a construction method for a pull-out resistant precast concrete composite pipe pile according to an exemplary embodiment of the present disclosure.
[0043] The meanings of the reference numerals in the above figures are as follows:
[0044] 1-Precast concrete pipe;
[0045] 2-Reinforcing cage;
[0046] 201-Longitudinal reinforcement;
[0047] 202-Circular stirrup;
[0048] 3- Slow-bonding prestressed steel strand;
[0049] 301-Continuous, slow-bonding prestressed steel strand;
[0050] 302 - Auxiliary slow-bonding prestressed steel strand;
[0051] 303 - Sheath;
[0052] 304 - Convex Ribs;
[0053] 305 - Adhesive;
[0054] 306 steel strand;
[0055] 4-Concrete core;
[0056] 5-Pipe pile joint;
[0057] 6-Anchors;
[0058] 7-Closed end cap;
[0059] 8-Ground;
[0060] 9-Foundation pit;
[0061] 10-Tensioning end;
[0062] 11 - Basics. Detailed Implementation
[0063] To make the objectives, technical solutions, and advantages of this disclosure clearer, the following detailed description is provided in conjunction with specific embodiments and the accompanying drawings.
[0064] However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of this disclosure. In the following detailed description, numerous specific details are set forth to provide a thorough understanding of embodiments of this disclosure for ease of explanation. However, it will be apparent that one or more embodiments may be practiced without these specific details. Furthermore, descriptions of well-known technologies are omitted in the following description to avoid unnecessarily obscuring the concepts of this disclosure.
[0065] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. The term "comprising" as used herein indicates the presence of features, steps, or operations, but does not exclude the presence or addition of one or more other features.
[0066] When using expressions such as "at least one of A, B, and C," the expression should generally be interpreted in accordance with the meaning commonly understood by a person skilled in the art (e.g., "a system having at least one of A, B, and C" should include, but is not limited to, systems having A alone, having B alone, having C alone, having A and B, having A and C, having B and C, and / or having A, B, and C, etc.). When using expressions such as "at least one of A, B, or C," the expression should generally be interpreted in accordance with the meaning commonly understood by a person skilled in the art (e.g., "a system having at least one of A, B, or C" should include, but is not limited to, systems having A alone, having B alone, having C alone, having A and B, having A and C, having B and C, and / or having A, B, and C, etc.).
[0067] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein are to be interpreted in a manner consistent with the context of this specification, and not in an idealized or overly rigid way.
[0068] Figure 1 This is a cross-sectional view of a precast concrete composite pipe pile according to an exemplary embodiment of the present disclosure; Figure 2 yes Figure 1 AA section view of precast concrete composite pipe pile.
[0069] According to one aspect of the inventive concept of this disclosure, a precast concrete composite pipe pile for pull-out resistance is provided, such as... Figure 1 and Figure 2 As shown, the precast concrete composite pipe pile includes: a precast concrete pipe 1, a reinforcing cage 2, a slow-bonding prestressed steel strand 3, and a concrete core 4. The number of precast concrete pipes 1 is at least two sections, which are constructed to be sequentially pressed into predetermined pile positions in the vertical direction. The reinforcing cage 2 is disposed inside the precast concrete pipe 1. One end of the continuous slow-bonding prestressed steel strand 301 is fixed at the bottom of the reinforcing cage 2 and has a first anchoring end, while the other end extends beyond the upper end of the precast concrete pipe 1. One end of the auxiliary slow-bonding prestressed steel strand 302 is fixed at the upper, middle, or lower part of the reinforcing cage and has a second anchoring end, while the other end extends beyond the upper end of the precast concrete pipe 1. The concrete core 4 is disposed inside the precast concrete pipe 1 and is cast and connected to at least two sections of the precast concrete pipe 1. In this case, the curing time of the slow-setting adhesive of the slow-setting prestressed steel strand 3 is later than the setting time of the concrete core 4. In response to the concrete core 4 reaching the preset threshold strength, the slow-setting prestressed steel strand 3 is tensioned until the slow-setting adhesive is cured.
[0070] In this embodiment, by setting a slow-bonding prestressed steel strand 3 inside the steel cage 2 of the pipe pile, the steel strand is tensioned after the concrete has solidified and reached the preset strength. In particular, the tensioning can be carried out after the foundation pit 9 has been excavated. The tensioning operation is simple and the tensioning effect is controllable.
[0071] According to some optional embodiments of this disclosure, in order to ensure that the pull-out pile has sufficient pull-out bearing capacity, the number of precast concrete pipes 1 is multiple, such as two, three or more.
[0072] According to some embodiments of this disclosure, the precast concrete composite pipe pile further includes a pipe pile joint 5, which is disposed between two adjacent precast concrete pipe sections 1. During construction, the first precast concrete pipe section 1 is pressed into the target area on the ground 8 using a pressing method, hammering method, or implantation method. The second precast concrete pipe section 1 is then hoisted onto the first precast concrete pipe section 1, and the two precast concrete pipe sections 1 are connected together through the pipe pile joint 5. After the connection strength reaches the preset requirements, the pile driving operation of the second precast concrete pipe section 1 continues. The above operation is repeated until all precast concrete pipe sections 1 are driven into the target pile position.
[0073] According to some embodiments of this disclosure, at least two precast concrete pipes 1 together define a concrete pouring space, and a steel cage 2 is hoisted into the concrete pouring space.
[0074] According to some embodiments of this disclosure, the loosely bonded prestressed steel strand 3 is fixed on the reinforcing cage 2, maintaining an overall vertical state with the other end extending beyond the top of the uppermost precast concrete pipe 1, so as to facilitate the tensioning operation in subsequent processes.
[0075] According to some embodiments of this disclosure, after the concrete pouring is completed, the concrete is poured together with at least two precast concrete pipes 1 and the reinforcing cage to form a whole, providing compressive strength, shear strength and a certain tensile strength, and forming a concrete core 4.
[0076] Figure 3 This is a partial structural schematic diagram of the slow-bonding prestressed steel strand of a precast concrete composite pipe pile according to an exemplary embodiment of the present disclosure. Figure 4 yes Figure 3 A partial structural schematic diagram of the slow-bonded prestressed steel strands of the precast concrete composite pipe pile, shown from another perspective.
[0077] According to some embodiments of this disclosure, such as Figure 3 and Figure 4 As shown, the slow-setting prestressed steel strand 3 includes a sheath 303, steel strands 306 disposed inside the sheath, and a slow-setting adhesive 305 filled between the two. During the setting process of the poured concrete, the sheath 303 is bonded to the concrete core 4. At this time, the slow-setting adhesive 305 located inside the sheath 303 has not yet reached its curing time.
[0078] According to some optional embodiments of this disclosure, a plurality of protruding ribs 304 are provided at intervals on the outer side of the sheath 303. The plurality of protruding ribs 304 form a plurality of annular grooves on the outer surface of the sheath 303 to improve the bonding strength between the sheath 303 and the concrete core 4 and prevent the two from moving relative to each other in the axial direction, which would lead to tension failure.
[0079] According to some optional embodiments of this disclosure, such as Figure 3 and Figure 4 As shown, the slow-bonding prestressed steel strand 3 includes: a full-length slow-bonding prestressed steel strand 301 and an auxiliary slow-bonding prestressed steel strand 302.
[0080] According to some embodiments of this disclosure, the loosely bonded prestressed steel strand 3 is fixed on the reinforcing cage 2. The full-length loosely bonded prestressed steel strand 301 is fixed at the bottom of the reinforcing cage 2 and has an anchoring end. The auxiliary loosely bonded prestressed steel strand 302 is fixed at the upper, middle or lower part of the reinforcing cage and has an anchoring end. The loosely bonded prestressed steel strand 3 and the longitudinal reinforcement 2 of the reinforcing cage extend from the top of the precast concrete pipe pile to anchor into the foundation. The loosely bonded prestressed steel strand 3 has a tensioning end at the top of the precast pipe pile. After the foundation pit is excavated, tensioning and anchoring are performed. Prestress is established in the precast concrete composite pipe pile body composed of the precast concrete pipe pile and the concrete core 4 to resist the axial tensile force generated by the buoyancy of the basement.
[0081] In this embodiment, the axial tensile force generated by the buoyancy of the basement on the precast concrete composite pipe pile is greatest at the pile top and gradually decreases from top to bottom, reaching zero at the pile bottom. Based on this, by using a continuous, slow-bonding prestressed steel strand 301 in conjunction with an auxiliary slow-bonding prestressed steel strand 302, the amount of slow-bonding prestressed steel strand 3 can be reduced. The lower end position of the auxiliary slow-bonding prestressed steel strand 302 can be determined according to the axial tensile force on the pile body. The auxiliary slow-bonding prestressed steel strand 302 can also be divided into different lengths for anchoring at different locations, thereby reducing the amount of steel used.
[0082] During the driving or hammering process of precast concrete pipe piles, the total resistance to the pile gradually increases with the increase in underground depth, and the driving force or hammering force on the pile body from bottom to top also gradually increases. Based on this, by controlling the wall thickness of the precast concrete pipe 1, specifically by gradually thinning each section of the multi-section precast concrete pipe 1 from top to bottom, the project cost can be effectively reduced.
[0083] According to some embodiments of this disclosure, the steel cage 2 includes: longitudinal bars 201 and annular stirrups 202.
[0084] According to some embodiments of this disclosure, the longitudinal reinforcement 201 is the longitudinal main structure of the reinforcing cage, and the annular stirrups 202 are arranged on the longitudinal reinforcement 201. Multiple longitudinal reinforcements 201 and multiple annular stirrups 202 combine to form a columnar structure. Figure 1 Only a portion of the stirrups are shown in the diagram. The annular stirrups 202 are installed along the length of the longitudinal reinforcement 201.
[0085] According to some embodiments of this disclosure, the precast concrete composite pipe pile further includes an anchor 6, which is disposed at the lower end of the loosely bonded prestressed steel strand 3.
[0086] According to some optional embodiments of this disclosure, the loosely bonded prestressed steel strand 3 is connected and fixed to the reinforcing cage 2, for example, by binding with wire for positioning. Anchors 6 are provided at the lower end of the loosely bonded prestressed steel strand 3 for anchoring. After the concrete core 4 has initially set, the anchors 6 are fixed together with the concrete core 4 to provide a lower support (anchor point) for subsequent tensioning operations.
[0087] According to some alternative embodiments of this disclosure, the anchor 6 is fixed to the reinforcing cage 2, for example by welding, and the lower end of the loosely bonded prestressed steel strand 3 is anchored to the anchor 6.
[0088] According to some optional embodiments of this disclosure, the number of slow-bonding prestressed steel strands 3 is six, of which three are auxiliary slow-bonding prestressed steel strands 302, and the continuous slow-bonding prestressed steel strands 301 and slow-bonding prestressed steel strands 302 are evenly arranged along the circumference of the reinforcing cage.
[0089] According to some embodiments of this disclosure, the precast concrete composite pipe pile also includes a closed end cap 7, which is disposed at the bottom of the lowest precast concrete pipe 1, and the closed end cap 7 has a flat bottom or a conical bottom.
[0090] In this embodiment, the sealing cap 7 seals the bottom of the lowest precast concrete pipe 1, which can prevent the concrete from coming into contact with external soil, groundwater, gravel, etc. during the concrete core pouring process, thus ensuring the quality of the concrete core 4.
[0091] Figure 5 This is a schematic diagram of the connection between the top of a precast concrete composite pipe pile for pull-out resistance and the foundation 11, according to an exemplary embodiment of the present disclosure.
[0092] In this embodiment, as Figure 5 As shown, the slow-bonded prestressed steel strand 3 and longitudinal reinforcement 201 are anchored into the foundation 11. The slow-bonded prestressed steel strand 3 is provided with a tensioning end on the top surface of the foundation. After the concrete of the foundation 11 reaches the predetermined strength, it is tensioned and anchored.
[0093] Figure 6 This is a flowchart of a construction method for a pull-out resistant precast concrete composite pipe pile according to an exemplary embodiment of the present disclosure.
[0094] According to another aspect of the inventive concept of this disclosure, a construction method for precast concrete composite pipe piles for pull-out resistance is also provided, including operations S601 to S606.
[0095] According to some embodiments of this disclosure, operation S601 includes: driving at least two precast concrete pipe sections into the target pile location until the top of the pipe pile is close to the ground.
[0096] According to some embodiments of this disclosure, operation S602 includes: placing a reinforcing cage into a precast concrete pipe, wherein one end of the loosely bonded prestressed steel strand is connected to the bottom of the reinforcing cage, and the other end extends beyond the upper end of the precast concrete pipe.
[0097] According to some embodiments of this disclosure, operation S603 includes: performing a concrete filling operation on the precast concrete pipe.
[0098] According to some embodiments of this disclosure, operation S604 includes: continuing the pile driving operation until the pile is driven to the predetermined position.
[0099] According to some embodiments of this disclosure, operation S605 includes: excavating the foundation pit before the adhesive of the loosely bonded prestressed steel strand has cured, and tensioning and anchoring the tensioned end of the loosely bonded prestressed steel strand.
[0100] According to some embodiments of this disclosure, operation S606 includes: performing foundation construction and then tensioning and anchoring the loosely bonded prestressed steel strands within the foundation.
[0101] According to some embodiments of this disclosure, the adhesive is allowed to cure while maintaining a preset tension.
[0102] According to some embodiments of this disclosure, the prestressed steel strands are kept vertical during concrete core grouting operations.
[0103] According to some embodiments of this disclosure, pile driving operations include pressing, hammering, or implantation.
[0104] The precast concrete composite pipe pile and construction method for pull-out resistance provided in the embodiments of this disclosure have the following beneficial effects.
[0105] Because the curing time of the adhesive in the slow-bonded prestressed steel strand can be preset, it can be laid, tensioned and anchored like unbonded prestressed steel strand. After the adhesive cures, it becomes a bonded prestressed steel strand without the need for grouting, making construction simple and convenient.
[0106] After the prestressed steel strands are tensioned, the tension is transmitted to their anchoring ends and acts on the concrete core inside the precast concrete pipe pile. The lower part of the concrete core is compressed, making the concrete core a pressure-dispersing anchor rod anchored inside the precast concrete pipe pile. This can fully utilize the friction between the inner wall of the precast concrete pipe pile and the concrete core, making the precast concrete pipe pile and the concrete core a single unit to form a composite precast concrete pipe pile, and establishing effective prestress in the pile body.
[0107] Slow-bonded prestressed steel strands become bonded prestressed steel strands after the adhesive has cured. The prestress within the pile body has good reliability, and since the steel strands are located inside the pipe pile, they have good corrosion resistance.
[0108] Because the prestressed steel strands with slow bonding are tensioned and establish prestress in the pile body, the joints of the precast prestressed composite pipe piles can be under pressure during operation, thus ensuring the reliability of the concrete pipe pile joints. The portion of the slow-bonded prestressed steel strands extending out of the pile top is anchored into the foundation and fixed after tensioning, which can ensure the reliability of the connection between the pile top and the foundation. Furthermore, under the action of prestress, it prevents the generation of cracks between the pile top and the foundation, ensuring the durability of the connection.
[0109] In addition to the full-length slow-bonded prestressed steel strands, the lower end of the auxiliary slow-bonded prestressed steel strands can be anchored at a suitable position according to the tension force on the pile body, so that the prestressing force established on the pile body matches the tension force on the pile due to anti-buoyancy. At the same time, the tensile strength of the slow-bonded prestressed steel strands is much higher than that of ordinary steel bars, which can significantly reduce the amount of steel used in anti-uplift piles, save energy and reduce emissions, and reduce project costs.
[0110] Depending on the stress on the pile body during construction, the wall thickness of the precast concrete pipe pile is gradually reduced from top to bottom, which can further reduce the project cost.
[0111] Precast concrete composite pipe piles retain the advantages of precast concrete pipe piles, such as simple construction, fast construction speed, high pile quality, and low cost. They also solve the shortcomings of precast concrete pipe piles, such as low tensile bearing capacity and poor reliability of pile joints and pile top connections when used as tensile piles. This has positive significance for promoting the application of precast concrete pipe piles in engineering, improving engineering quality and industrialization, reducing engineering costs, and saving energy and reducing emissions.
[0112] The embodiments of this disclosure have been described in detail above with reference to the accompanying drawings. It should be noted that implementations not illustrated or described in the drawings or the main text of the specification are forms known to those skilled in the art and have not been described in detail. Furthermore, the definitions of the various components described above are not limited to the specific structures, shapes, or methods mentioned in the embodiments, and those skilled in the art can easily modify or substitute them.
[0113] It should also be noted that, in the specific embodiments of this disclosure, unless otherwise stated otherwise, the numerical parameters in this specification and the appended claims are approximate values and can be changed according to the desired characteristics obtained from the content of this disclosure. Specifically, all numbers used in the specification and claims to indicate dimensions, range conditions, etc., of the composition should be understood to be modified by the term "about" in all cases. Generally, this means that there may be variations of ±10% in some embodiments, ±5% in some embodiments, ±1% in some embodiments, and ±0.5% in some embodiments.
[0114] Those skilled in the art will understand that the features described in the various embodiments and / or claims of this disclosure can be combined or combined in various ways, even if such combinations or combinations are not explicitly described in this disclosure. In particular, the features described in the various embodiments and / or claims of this disclosure can be combined or combined in various ways without departing from the spirit and teachings of this disclosure. All such combinations and / or combinations fall within the scope of this disclosure.
[0115] The specific embodiments described above further illustrate the purpose, technical solutions, and beneficial effects of this disclosure. It should be understood that the above descriptions are merely specific embodiments of this disclosure and are not intended to limit this disclosure. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure should be included within the protection scope of this disclosure.
Claims
1. A construction method for precast concrete composite pipe piles for pull-out resistance, characterized in that, The precast concrete composite pipe piles used for pull-out resistance include: At least two precast concrete pipes are configured to be pressed into the pre-set pile positions in the vertical direction in sequence; A reinforcing cage is installed inside the precast concrete pipe; The lower end of the loosely bonded prestressed steel strand is anchored at the bottom of the precast concrete pipe, and the upper end extends beyond the upper end of the precast concrete pipe. A concrete core is disposed inside the precast concrete pipe, and the concrete core is cast and connected together with at least two sections of the precast concrete pipe. The curing time of the slow-setting adhesive of the slow-bonding prestressed steel strand is later than the setting time of the concrete core. In response to the concrete core reaching a preset threshold strength, the slow-bonding prestressed steel strand is tensioned until the slow-setting adhesive cures. The slow-bonding prestressed steel strand includes: A long, slow-bonded prestressed steel strand is provided with a first anchoring end at the bottom of the precast concrete composite pipe pile and a first tensioning end at the top of the precast concrete composite pipe pile. An auxiliary, slow-bonding prestressed steel strand is provided with a second anchoring end in the upper, middle or lower part of the precast concrete composite pipe pile, and a second tensioning end is provided at the top of the precast concrete composite pipe pile. The number of auxiliary, slow-bonding prestressed steel strands is multiple, and the lengths of the multiple auxiliary, slow-bonding prestressed steel strands are different. The construction method includes: Drive at least two precast concrete pipe sections to the target pile location until the top of the pipe pile is close to the ground. The reinforcing cage is placed into the precast concrete pipe. The lower end of the continuous slow-bonding prestressed steel strand is anchored and fixed to the bottom of the reinforcing cage. The lower end of the auxiliary slow-bonding prestressed steel strand is anchored and fixed to the upper, middle or lower part of the reinforcing cage. The other end of the slow-bonding prestressed steel strand extends beyond the upper end of the precast concrete pipe. The precast concrete pipe is then filled with concrete. Continue pile driving until the piles are driven to the predetermined elevation; Before the adhesive of the loosely bonded prestressed steel strand cures, the foundation pit is excavated, and the loosely bonded prestressed steel strand is tensioned and anchored. The foundation construction is carried out, and the loosely bonded prestressed steel strands are tensioned and anchored within the foundation; In this process, the adhesive is allowed to cure while maintaining a preset tension.
2. The construction method according to claim 1, characterized in that, During the concrete core-filling operation, the slow-bonded prestressed steel strands are kept vertical.
3. The construction method according to claim 1, characterized in that, The pile driving operation includes the pressing method, the hammering method, or the implantation method.
4. The construction method according to claim 1, characterized in that, The precast concrete composite pipe piles used for pull-out resistance also include: Pipe pile joints are set between two adjacent sections of the precast concrete pipe, and the wall thickness of at least two sections of the precast concrete pipe decreases sequentially from top to bottom.
5. The construction method according to claim 1, characterized in that, The steel cage includes: Longitudinal reinforcement; Circular stirrups are placed on the longitudinal reinforcement; The slow-bonding prestressed steel strand is fixed to the reinforcing cage.
6. The construction method according to claim 1, characterized in that, The number of continuous, slow-bonded prestressed steel strands is at least two, and the continuous, slow-bonded prestressed steel strands and the auxiliary slow-bonded prestressed steel strands are evenly arranged along the circumference of the reinforcing cage.
7. The construction method according to claim 1, characterized in that, The precast concrete composite pipe piles used for pull-out resistance also include: A closed end cap is installed at the bottom of the precast concrete pipe at the lowest point. The closed end cap has a flat bottom or a conical bottom.