Fabricated composite pre-buried steel sheet pile structure based on foundation pit enclosure and construction method

Abstract

The application discloses a fabricated composite pre-buried steel sheet pile structure based on a foundation pit support and a construction method, relates to the technical field of foundation pit support, and aims at the problems of stable connection of nodes depending on prestress application and lack of deformation compensation mechanism.In the application, on one hand, adjustable supports are used to complete accurate engagement between the lock ports of the foundation pit side plate body and the soil side plate body, to make up for the leakage risk of the lock ports of the steel sheet pile, to enhance the overall bending stiffness in soft soil areas, and to adapt to the construction requirements of deep foundation pits and high underground water level working conditions; on the other hand, the foundation pit side plate body and the soil side plate body are used as flexible supporting structures, and the concrete face plate is used as a rigid structure, the flexible supporting structures actively bear the earth pressure and form a waterproof barrier, the rigid structure increases the contact area to disperse the earth pressure and reduce local deformation, and the two structures form a composite supporting system of "rigidity and flexibility combined", which is beneficial to the smooth implementation of the foundation pit support.

Description

Technical Field

[0001] This invention relates to the field of foundation pit support technology, specifically to a prefabricated composite embedded steel sheet pile structure and construction method based on foundation pit support. Background Technology

[0002] Currently, the main forms of foundation pit retaining structures are cast-in-place concrete support systems, steel composite supports, and traditional steel sheet piles. Although cast-in-place concrete structures have high rigidity, they have problems such as long construction cycles (requiring a 28-day curing period), inability to be reused, and the generation of construction waste.

[0003] Traditional sheet pile support has insufficient bending stiffness, which can easily lead to excessive deformation in deep foundation pits. The water-stopping effect depends on the interlocking accuracy, which poses a risk of leakage. The construction process is also complex and requires the use of equipment such as hydraulic jacks. The stiffness of the retaining system is often improved by adopting a double-row pile structure, which leads to a doubling of the number of components and poor economic efficiency. The standardization of prefabricated components is low, and misalignment is prone to occur during on-site splicing, affecting the continuity of water-stopping.

[0004] In conjunction with the above, it should be noted that: In the prior art, the invention patent with publication number CN108612081A can be referred to, which uses grouting reinforcement and prestressed hollow tie rods to complete the assembly of composite sheet piles to form a stable and waterproof foundation pit retaining wall. However, in the construction process, the Larssen steel sheet piles and mother units used do not have the ability to be assembled indiscriminately. Instead, it increases the variety of components and the probability of assembly errors. Moreover, the node connection relies on the application of prestress and lacks a deformation compensation mechanism. In soft soil areas, stress concentration is easily caused by soil creep, which can lead to the failure of the retaining wall bearing or even deformation and water seepage. Therefore, this application proposes a solution. Summary of the Invention

[0005] The purpose of this invention is to provide a prefabricated composite embedded steel sheet pile structure and construction method based on foundation pit retaining, in order to solve the problems of node stability connection relying on prestressing and lack of deformation compensation mechanism.

[0006] The objective of this invention can be achieved through the following technical solution: a prefabricated composite embedded steel sheet pile structure based on foundation pit support, comprising a pile plate, wherein the pile plate comprises a soil side plate and a foundation pit side plate, and the soil side plate is inserted in reverse to the outside of the soil side of an adjacent pair of foundation pit side plates, an adjustable support assembly is provided between an adjacent pair of foundation pit side plates, and a fixed support assembly is provided between an adjacent pair of soil side plates, wherein the adjustable support assembly and the fixed support assembly together complete the fixation of the pile plate; The adjustable support assembly includes a split plate and a split coupling. The split plate has a support rod connected to the split coupling installed on the soil side via a locking screw. An elastic rod is installed in the middle of the support rod. The split coupling is locked to the ends of a pair of adjacent pit side plates. The fixed support assembly includes an integral plate and an integral coupling. The integral plate has a connecting plate connected to the integral coupling installed on the pit side. The integral coupling is locked to the ends of a pair of adjacent soil side plates. A corner plate is installed on the foundation pit side of the soil side plate located at the corner, and an outer locking hoop is locked to the end of the soil side plate located at the corner.

[0007] A further configuration is provided: the ends of the pile plates are provided with end locks, and the end locks of an adjacent pair of pile plates are close to each other but do not contact each other.

[0008] The configuration is further defined as follows: the end lock is in the shape of a "J", and the ends of the split coupling and the integral coupling are also in the shape of a "J", and the split coupling and the integral coupling are in clearance fit with the end lock.

[0009] Further configuration: side pressure plates connected to the foundation pit side plate are installed at both ends of the split connecting plate, and an adjustment hole is opened in the middle of the split connecting plate. A locking screw is installed on the split connecting plate through the adjustment hole. The locking screw passes through the split connecting plate and is connected to the elastic rod. The elastic rod is arc-shaped and the concave side of the arc surface faces the soil side.

[0010] The integral connecting plate is further configured such that: both ends of the integral connecting plate are fitted with adhesive plates that connect to the soil side plates.

[0011] A further configuration is provided: a pit-side concrete slab is installed on the pit-side side of the pit side plate, and an anchor bolt connected to a locking screw is installed on the soil side of the pit-side concrete slab.

[0012] A further configuration is provided: a soil-side concrete slab is installed on the soil-side side of the soil-side plate, and the spacing between the soil-side concrete slab and the soil-side plate, and between the pit-side concrete slab and the pit-side plate are the same.

[0013] A further configuration is provided: a distributed optical fiber sensor is installed between the split coupling, the integrated coupling, and the end lock coupling.

[0014] The construction method of prefabricated composite embedded steel sheet pile structure based on foundation pit retaining includes the following steps: precise driving of steel sheet piles, hoisting and locking of concrete panels, and deformation coordination control.

[0015] The present invention has the following beneficial effects: This invention addresses the problem of unstable node connections relying on prestressing and lacking deformation compensation mechanisms. It achieves continuous insertion of a single structure by using soil side plates and foundation pit side plates with identical structural designs to form a steel sheet pile structure. With the cooperation of fixed support components and adjustable support components, it can effectively perform corresponding deformation compensation, ensuring that the composite pre-embedded steel sheet piles can improve bending stiffness, prevent deformation, and achieve deep water-locking function during the construction of foundation pit retaining. During the deformation compensation stage: on the one hand, adjustable support is used to achieve precise interlocking between the pit side plate and the soil side plate, compensating for the leakage risk at the steel sheet pile interlocking point, while enhancing the overall bending stiffness in soft soil areas to meet the construction requirements of deep pits and high groundwater levels; on the other hand, the pit side plate and the soil side plate are used as flexible support structures in conjunction with concrete panels as rigid structures. The flexible support structure actively bears the soil pressure and forms a waterproof barrier, while the rigid structure increases the contact area to disperse the soil pressure and reduce local deformation. Together, they form a composite support system that combines rigidity and flexibility, which is conducive to the smooth implementation of pit protection. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a top view of the present invention; Figure 3 This is a partial structural breakdown diagram of the main body of the steel sheet pile of the present invention; Figure 4 This is a schematic diagram of the adjustable support assembly of the present invention; Figure 5 This is a schematic diagram of the installation structure of the fixed support assembly of the present invention; Figure 6 This is a schematic diagram of the installation of the foundation pit side concrete slab according to the present invention; Figure 7 This is a schematic diagram of the installation of the double-sided concrete slab of the present invention; Figure 8 This is a schematic diagram of the installation of the soil-side concrete slab of the present invention.

[0018] In the diagram: 1. Pile plate; 2. Split joint plate; 3. Split coupling; 4. Integrated joint plate; 5. Turning plate; 6. External locking coupling; 7. Adjustment hole; 8. Side pressure plate; 9. Supporting rod; 10. Locking screw; 11. End locking coupling; 12. Elastic rod; 13. Connecting plate; 14. Integrated coupling; 15. Adhesive plate; 16. Anchor bolt; 17. Concrete slab on the side of the foundation pit; 18. Concrete slab on the side of the soil. Detailed Implementation

[0019] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] Example 1: To address the problem that stable node connections rely on prestressing and lack a deformation compensation mechanism, the following technical solution is proposed: Reference Figure 1 - Figure 4 As shown, the prefabricated composite embedded steel sheet pile structure based on the foundation pit retaining structure in this embodiment includes a pile plate 1. The pile plate 1 includes a soil side plate and a foundation pit side plate. The soil side plate is inserted into the outside of the soil side of an adjacent pair of foundation pit side plates. An adjustable support component is provided between the adjacent pair of foundation pit side plates, and a fixed support component is provided between the adjacent pair of soil side plates. The adjustable support component and the fixed support component together complete the fixation of the pile plate 1. Reference Figure 3 and Figure 4 As shown, the adjustable support assembly includes a split plate 2 and a split coupling 3. The side of the split plate 2 near the soil is equipped with a support rod 9 connected to the split coupling 3 via a locking screw 10. An elastic rod 12 is installed in the middle of the support rod 9. The split coupling 3 is locked to the ends of a pair of adjacent pit side plates. The fixed support assembly includes an integral connecting plate 4 and an integral coupling 14. A connecting plate 13 connected to the integral coupling 14 is installed on the side of the integral connecting plate 4 near the foundation pit. The integral coupling 14 is locked to the ends of a pair of adjacent soil side plates. The pre-embedding process of the steel sheet piles for the foundation pit retaining wall is as follows: a high-frequency hydraulic vibratory hammer is used in conjunction with an infrared sensing positioning system to enable the pile sheet 1 to be accurately locked without difference by the high-frequency hydraulic vibratory hammer. With the matching addition of the fixed support assembly and the adjustable support assembly, the prefabricated composite pre-embedded steel sheet pile structure meets the requirements for foundation pit deformation control. The corner side plates of the soil body are jointly installed with the foundation pit side of the foundation pit, and the ends of the corner side plates of the soil body are jointly locked with the outer locking hoop 6. It should be noted that when the current soil side plate is installed at the corner, that is, when the support construction of the corner of the foundation pit is carried out, the corner plate 5 and the outer locking hoop 6 together form a locking system to achieve the purpose of adapting to the shape of the foundation pit for adaptive support. Moreover, the soil side plates with the same structural design can be effectively inserted and adapted, reducing the probability of high assembly error rate caused by numerous components. Reference Figure 5 As shown, the end of the pile plate 1 is provided with an end locking hoop 11. The end locking hoops 11 of an adjacent pair of pile plates 1 are close to each other but do not contact each other. The end locking hoop 11 is in the shape of "J". The ends of the split coupling 3 and the integral coupling 14 are also in the shape of "J". The split coupling 3 and the integral coupling 14 are all in clearance fit with the end locking hoop 11. When the pile plate 1 is pre-embedded, it can achieve adaptive intermittent fitting by using the end locking hoops 11 to cooperate with the fixed support component and the split coupling 3 and the integral coupling 14 on the adjustable support component respectively. The adjustable support component completes the precise interlocking between the locks, which makes up for the leakage risk at the lock of the steel sheet pile. Reference Figure 3 and Figure 5 As shown, the two ends of the split plate 2 are equipped with side pressure plates 8 that are connected to the side plate of the foundation pit, and the middle of the split plate 2 is provided with adjustment holes 7. The split plate 2 is equipped with locking screws 10 through the adjustment holes 7. The locking screws 10 pass through the split plate 2 and are connected to the elastic rod 12. The elastic rod 12 is arc-shaped and the concave side of the arc surface faces the soil side. The two ends of the integral plate 4 are equipped with bonding plates 15 that are connected to the side plate of the soil. Reference Figure 6 - Figure 8 As shown, a pit-side concrete slab 17 is installed on the pit-side plate near the pit, and an anchor bolt 16 connected to the locking screw 10 is installed on the soil side of the pit-side concrete slab 17. A soil-side concrete slab 18 is installed on the soil-side plate near the soil. The spacing between the soil-side concrete slab 18 and the soil-side plate, and between the pit-side concrete slab 17 and the pit-side plate is the same. The foundation pit retaining structure, which consists of two or three concrete slabs 17 on the pit side, concrete slabs 18 on the soil side, and pile slabs 1, can effectively realize the use of various foundation pit types, including but not limited to: foundation pits that need to strengthen the support rigidity or repair the local deformation of steel sheet piles, permanent retaining structures, or foundation pits that need to be covered with an external waterproof layer.

[0021] Basic Principle: In this invention, the steel sheet pile structure, composed of soil side plates and foundation pit side plates with identical structural designs, enables continuous insertion of a single structure. Combined with fixed and adjustable support components, it effectively compensates for deformation, ensuring that during the construction of the composite embedded steel sheet piles for foundation pit support, it achieves increased bending stiffness, prevents deformation, and provides deep water-locking functionality. The deformation compensation stage includes: On the one hand, adjustable support is used to achieve precise interlocking between the pit side plate and the soil side plate, compensating for the leakage risk at the steel sheet pile interlocking point. At the same time, it enhances the overall bending stiffness in soft soil areas, adapting to the construction needs of deep pits and high groundwater levels. On the other hand, the pit side plate and the soil side plate are used as flexible support structures in combination with concrete panels as rigid structures. The flexible support structure actively bears the soil pressure and forms a waterproof barrier, while the rigid structure increases the contact area, disperses the soil pressure, and reduces local deformation. Together, they form a composite support system that combines rigidity and flexibility, which is conducive to the smooth implementation of pit protection.

[0022] Example 2: This example further optimizes the deformation collaborative control process in Example 1 using intelligent methods. Distributed fiber optic sensors are installed between the mating surfaces of the split coupling 3, the integrated coupling 14, and the end locking coupling 11, as shown in the reference. Figure 6 As shown, although the split coupling 3 and the integrated coupling 14 are different components, they have the same structure. Therefore, the mating surface is represented as the "interlocking surface" between adjacent pile plates 1. The distributed optical fiber sensor is connected to the active control module connected to the terminal host computer. The active control module includes a strain detection end, a strain distribution analysis end, and an execution control end that are connected in communication. The strain detection end is used to acquire strain values ​​during the assembly of composite steel sheet piles and send the strain values ​​to the stress distribution analysis end; The strain distribution analysis terminal performs analysis operations after receiving the strain values: S1: Obtain the strain value, which represents the strain distribution parameter between the joint surfaces of the split coupling 3, the integral coupling 14 and the end locking coupling 11. The strain distribution parameter is represented as the ratio between the change in contact length of the joint surface and the initial contact length of the joint surface, and is measured by a distributed optical fiber sensor set between the joint surfaces of the split coupling 3, the integral coupling 14 and the end locking coupling 11. S2: According to the formula: Obtain stress value Where E is the elastic modulus of the sheet pile. This represents the change in contact length at the mating surfaces. This represents the initial contact length of the mating surfaces; S3: Stress value Evaluation information is obtained by comparing and analyzing the stress threshold preset in the active control module; The evaluation information is then sent to the strain distribution analysis terminal, which generates positive and negative control signals based on the evaluation information. These signals are then sent to the execution control terminal. The generation process of the positive and negative control signals is as follows: When the stress value is greater than the stress threshold, a positive control signal is generated and sent to the control execution terminal. When the stress value is less than the stress threshold, a reverse control signal is generated and sent to the control execution terminal. When the stress value is within the stress threshold, no signal is generated.

[0023] After receiving the positive and negative control signals, the control terminal sends a control signal to the host computer to remind the construction personnel to actively control the pre-embedded assembly of the steel sheet piles. The control process is as follows: Action 1: If a positive control signal is received, it indicates that there is a risk of leakage at the joint surface of the split coupling 3, the integrated coupling 14 and the end lock 11. At this time, the locking screw 10 is manually rotated inward through the hydraulic fine adjustment device. The locking screw 10 drives the split coupling 3 to move closer to the soil side through the elastic rod 12, thereby squeezing the joint between the split coupling 3 and the end lock 11 and eliminating the risk of leakage. Action 2: If a reverse control signal is received, it indicates that there is a risk of stress damage at the joint surface of the split coupling 3, the integrated coupling 14, and the end lock coupling 11. At this time, the locking screw 10 is manually turned outward through the hydraulic fine adjustment device. The locking screw 10 drives the split coupling 3 to move closer to the pit side through the elastic rod 12, thereby widening the joint between the split coupling 3 and the end lock coupling 11 and eliminating the risk of stress damage.

[0024] It should be noted that this intelligent active control module is based on intelligent stress detection combined with active manual control to achieve early warning function. It can provide timely action guidance when stress damage or stress damage and leakage risk caused by excessive joints occur during the pre-embedding of composite steel sheet piles.

[0025] Example 3: This example combines the technical content of Examples 1 and 2 to form a construction method for a prefabricated composite embedded steel sheet pile structure based on foundation pit support, including the following steps: The precise driving process of sheet piles: A high-frequency hydraulic vibratory hammer combined with an infrared sensor positioning system is used to ensure precise locking of the sheet piles 1 without any discrepancies. This is further enhanced by the appropriate installation of fixed and adjustable support components, ensuring that the prefabricated composite embedded sheet pile structure meets the requirements for foundation pit deformation control. Specifically: The end locking 11 between each other can be used to cooperate with the split coupling 3 and the integrated coupling 14 on the fixed support component and the adjustable support component to achieve adaptive intermittent fitting, and the adjustable support component can complete the precise interlocking between the locking joints to make up for the leakage risk at the locking joint of the steel sheet pile. When the current soil side plate is installed at the corner, that is, when the corner support construction of the foundation pit is carried out, the corner plate 5 and the outer locking hoop 6 together form a locking system to achieve the purpose of adapting to the shape of the foundation pit for adaptive support. Moreover, the soil side plates with the same structural design can be effectively inserted and adapted, reducing the probability of a high assembly error rate caused by numerous components. Concrete panel hoisting and locking process: The foundation pit retaining structure composed of the foundation pit side concrete slab 17, the soil side concrete slab 18 and the pile plate 1 set in pairs or in all three can effectively realize the use of various foundation pit types, including but not limited to: foundation pits that need to strengthen the support rigidity or repair the local deformation of steel sheet piles, permanent retaining structures or foundation pits that need to be covered with an external waterproof layer, etc. After installation, it forms an integral foundation pit retaining structure with pile plate 1. The integral foundation pit retaining structure uses the foundation pit side plate and soil side plate as flexible support structure and concrete panel as rigid structure. The flexible support structure actively bears the soil pressure and forms a waterproof barrier, while the rigid structure increases the contact area, disperses the soil pressure, and reduces local deformation. Deformation Coordination Control Process: During the foundation pit support process, strain values ​​are acquired during the assembly of composite steel sheet piles, and stress values ​​are obtained through numerical calculations. Positive and negative control signals are generated based on the comparison and analysis results of the stress values ​​and stress thresholds. The control stage involves: If a positive control signal is received, it indicates that there is a risk of leakage at the joint surface of the split coupling 3, the integrated coupling 14 and the end lock 11. At this time, the locking screw 10 is manually rotated inward by the hydraulic fine adjustment device. The locking screw 10 drives the split coupling 3 to move closer to the soil side through the elastic rod 12, thereby squeezing the joint between the split coupling 3 and the end lock 11 and eliminating the risk of leakage. If a reverse control signal is received, it indicates that there is a risk of stress damage at the joint surface of the split coupling 3, the integrated coupling 14, and the end lock coupling 11. At this time, the locking screw 10 is manually turned outward by the hydraulic fine adjustment device. The locking screw 10 drives the split coupling 3 to move closer to the pit side through the elastic rod 12, thereby widening the joint between the split coupling 3 and the end lock coupling 11 and eliminating the risk of stress damage.

[0026] In summary, the steel sheet pile structure, which is composed of soil side plates and foundation pit side plates with the same structural design, can complete the continuous insertion of a single structure. With the help of fixed support components and adjustable support components, it can effectively carry out the corresponding deformation compensation, and ensure that the composite pre-embedded steel sheet pile can improve the bending stiffness, avoid deformation and achieve deep water-locking function during the construction of the foundation pit retaining. The deformation compensation stage involves: on the one hand, using adjustable support to achieve precise interlocking between the pit side plate and the soil side plate, compensating for the leakage risk at the steel sheet pile interlocking point, and on the other hand, enhancing the overall bending stiffness in soft soil areas to meet the construction needs of deep pits and high groundwater levels. On the other hand, the pit side plate and soil side plate are used as flexible support structures in combination with concrete panels as rigid structures. The flexible support structure actively bears the soil pressure and forms a waterproof barrier, while the rigid structure increases the contact area, disperses the soil pressure, and reduces local deformation. Together, they form a composite support system that combines rigidity and flexibility, which is conducive to the smooth implementation of pit protection.

[0027] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to specific implementations. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A prefabricated composite embedded steel sheet pile structure based on foundation pit retaining, comprising a pile sheet (1), characterized in that: The pile plate (1) includes a soil side plate and a pit side plate. The soil side plate is inserted into the outside of the soil side of an adjacent pair of pit side plates. An adjustable support assembly is provided between the adjacent pair of pit side plates, and a fixed support assembly is provided between the adjacent pair of soil side plates. The adjustable support assembly and the fixed support assembly together complete the fixation of the pile plate (1). The adjustable support assembly includes a split plate (2) and a split coupling (3). The split plate (2) is equipped with a support rod (9) connected to the split coupling (3) via a locking screw (10) on the soil side. An elastic rod (12) is installed in the middle of the support rod (9). The split coupling (3) is locked to the ends of a pair of adjacent pit side plates. The fixed support assembly includes an integral plate (4) and an integral clamp (14). The integral plate (4) is equipped with a connecting plate (13) connected to the integral clamp (14) on the side near the foundation pit. The integral clamp (14) is locked to the ends of a pair of adjacent soil side plates. A corner plate (5) is installed on the foundation pit side of the soil side plate at the corner, and an outer locking hoop (6) is locked at the end of the soil side plate at the corner. The end of the pile plate (1) is provided with an end lock (11). The end locks (11) of an adjacent pair of pile plates (1) are close to each other but do not contact each other. The end locks (11) are in the shape of "J". The ends of the split coupling (3) and the integral coupling (14) are also in the shape of "J". The split coupling (3) and the integral coupling (14) are both clearance-fitted with the end locks (11). The two ends of the split plate (2) are equipped with side pressure plates (8) that are connected to the side plate of the foundation pit. An adjustment hole (7) is provided in the middle of the plate (2). The split plate (2) is equipped with a locking screw (10) through the adjustment hole (7). The locking screw (10) passes through the split plate (2) and is connected to the elastic rod (12). The elastic rod (12) is arc-shaped and the concave side of the arc faces the soil side. A foundation pit side concrete plate (17) is installed on the foundation pit side plate near the foundation pit. An anchor bolt (16) connected to the locking screw (10) is installed on the soil side of the foundation pit side concrete plate (17).

2. The prefabricated composite embedded steel sheet pile structure based on foundation pit support according to claim 1, characterized in that, The two ends of the integrated connecting plate (4) are fitted with adhesive plates (15) that connect to the soil side plates.

3. The prefabricated composite embedded steel sheet pile structure based on foundation pit support according to claim 1, characterized in that, A soil side concrete plate (18) is installed on the soil side of the soil side plate. The soil side concrete plate (18) and the soil side plate, and the pit side concrete plate (17) and the pit side plate are spaced at the same distance.

4. The prefabricated composite embedded steel sheet pile structure based on foundation pit retaining as described in claim 1, characterized in that, A distributed optical fiber sensor is installed between the split coupling (3), the integrated coupling (14), and the end lock coupling (11).

5. A construction method for a prefabricated composite embedded steel sheet pile structure based on foundation pit support, used for the prefabricated composite embedded steel sheet pile structure based on foundation pit support as described in any one of claims 1-4, characterized in that, The process includes the following steps: precise driving of sheet piles, hoisting and locking of concrete panels, and deformation control.

Images